yarn install failed on xenial

travis-error.log

```
g++ '-DNODE_GYP_MODULE_NAME=binding' '-DUSING_UV_SHARED=1' '-DUSING_V8_SHARED=1' '-DV8_DEPRECATION_WARNINGS=1' '-DV8_DEPRECATION_WARNINGS' '-DV8_IMMINENT_DEPRECATION_WARNINGS' '-D_LARGEFILE_SOURCE' '-D_FILE_OFFSET_BITS=64' '-DOPENSSL_THREADS' '-DBUILDING_NODE_EXTENSION' -I/home/travis/.node-gyp/12.0.0/include/node -I/home/travis/.node-gyp/12.0.0/src -I/home/travis/.node-gyp/12.0.0/deps/openssl/config -I/home/travis/.node-gyp/12.0.0/deps/openssl/openssl/include -I/home/travis/.node-gyp/12.0.0/deps/uv/include -I/home/travis/.node-gyp/12.0.0/deps/zlib -I/home/travis/.node-gyp/12.0.0/deps/v8/include -I../../nan -I../src/libsass/include  -fPIC -pthread -Wall -Wextra -Wno-unused-parameter -m64 -O3 -fno-omit-frame-pointer -fno-rtti -fno-exceptions -std=gnu++1y -std=c++0x -MMD -MF ./Release/.deps/Release/obj.target/binding/src/binding.o.d.raw   -c -o Release/obj.target/binding/src/binding.o ../src/binding.cpp
In file included from ../../nan/nan_converters.h:67:0,
                 from ../../nan/nan.h:222,
                 from ../src/binding.cpp:1:
../../nan/nan_converters_43_inl.h: In static member function ‘static Nan::imp::ToFactoryBase<v8::Boolean>::return_t Nan::imp::ToFactory<v8::Boolean>::convert(v8::Local<v8::Value>)’:
../../nan/nan_converters_43_inl.h:18:51: warning: ‘v8::MaybeLocal<v8::Boolean> v8::Value::ToBoolean(v8::Local<v8::Context>) const’ is deprecated: ToBoolean can never throw. Use Local version. [-Wdeprecated-declarations]
       val->To ## TYPE(isolate->GetCurrentContext())                            \
                                                   ^
../../nan/nan_converters_43_inl.h:22:1: note: in expansion of macro ‘X’
 X(Boolean)
 ^
In file included from /home/travis/.node-gyp/12.0.0/include/node/v8-internal.h:14:0,
                 from /home/travis/.node-gyp/12.0.0/include/node/v8.h:25,
                 from /home/travis/.node-gyp/12.0.0/include/node/node.h:63,
                 from ../../nan/nan.h:53,
                 from ../src/binding.cpp:1:
/home/travis/.node-gyp/12.0.0/include/node/v8.h:2524:63: note: declared here
                     V8_WARN_UNUSED_RESULT MaybeLocal<Boolean> ToBoolean(
                                                               ^
/home/travis/.node-gyp/12.0.0/include/node/v8config.h:322:3: note: in definition of macro ‘V8_DEPRECATE_SOON’
   declarator __attribute__((deprecated(message)))
   ^
In file included from ../../nan/nan_converters.h:67:0,
                 from ../../nan/nan.h:222,
                 from ../src/binding.cpp:1:
../../nan/nan_converters_43_inl.h: In static member function ‘static Nan::imp::ValueFactoryBase<bool>::return_t Nan::imp::ToFactory<bool>::convert(v8::Local<v8::Value>)’:
../../nan/nan_converters_43_inl.h:37:57: warning: ‘v8::Maybe<bool> v8::Value::BooleanValue(v8::Local<v8::Context>) const’ is deprecated: BooleanValue can never throw. Use Isolate version. [-Wdeprecated-declarations]
   return val->NAME ## Value(isolate->GetCurrentContext());                     \
                                                         ^
../../nan/nan_converters_43_inl.h:40:1: note: in expansion of macro ‘X’
 X(bool, Boolean)
 ^
In file included from /home/travis/.node-gyp/12.0.0/include/node/v8-internal.h:14:0,
                 from /home/travis/.node-gyp/12.0.0/include/node/v8.h:25,
                 from /home/travis/.node-gyp/12.0.0/include/node/node.h:63,
                 from ../../nan/nan.h:53,
                 from ../src/binding.cpp:1:
/home/travis/.node-gyp/12.0.0/include/node/v8.h:2562:51: note: declared here
                 V8_WARN_UNUSED_RESULT Maybe<bool> BooleanValue(
                                                   ^
/home/travis/.node-gyp/12.0.0/include/node/v8config.h:307:3: note: in definition of macro ‘V8_DEPRECATED’
   declarator __attribute__((deprecated(message)))
   ^
In file included from ../../nan/nan_new.h:189:0,
                 from ../../nan/nan.h:223,
                 from ../src/binding.cpp:1:
../../nan/nan_implementation_12_inl.h: In static member function ‘static Nan::imp::FactoryBase<v8::StringObject>::return_t Nan::imp::Factory<v8::StringObject>::New(v8::Local<v8::String>)’:
../../nan/nan_implementation_12_inl.h:356:37: error: no matching function for call to ‘v8::StringObject::New(v8::Local<v8::String>&)’
   return v8::StringObject::New(value).As<v8::StringObject>();
                                     ^
In file included from /home/travis/.node-gyp/12.0.0/include/node/node.h:63:0,
                 from ../../nan/nan.h:53,
                 from ../src/binding.cpp:1:
/home/travis/.node-gyp/12.0.0/include/node/v8.h:5380:23: note: candidate: static v8::Local<v8::Value> v8::StringObject::New(v8::Isolate*, v8::Local<v8::String>)
   static Local<Value> New(Isolate* isolate, Local<String> value);
                       ^
/home/travis/.node-gyp/12.0.0/include/node/v8.h:5380:23: note:   candidate expects 2 arguments, 1 provided
In file included from ../../nan/nan_new.h:189:0,
                 from ../../nan/nan.h:223,
                 from ../src/binding.cpp:1:
../../nan/nan_implementation_12_inl.h:356:58: error: expected primary-expression before ‘>’ token
   return v8::StringObject::New(value).As<v8::StringObject>();
                                                          ^
../../nan/nan_implementation_12_inl.h:356:60: error: expected primary-expression before ‘)’ token
   return v8::StringObject::New(value).As<v8::StringObject>();
                                                            ^
In file included from /home/travis/.node-gyp/12.0.0/include/node/node_object_wrap.h:26:0,
                 from ../../nan/nan.h:55,
                 from ../src/binding.cpp:1:
../../nan/nan_object_wrap.h: In destructor ‘virtual Nan::ObjectWrap::~ObjectWrap()’:
../../nan/nan_object_wrap.h:24:25: error: ‘class Nan::Persistent<v8::Object>’ has no member named ‘IsNearDeath’
     assert(persistent().IsNearDeath());
                         ^
../../nan/nan_object_wrap.h: In static member function ‘static void Nan::ObjectWrap::WeakCallback(const v8::WeakCallbackInfo<Nan::ObjectWrap>&)’:
../../nan/nan_object_wrap.h:127:26: error: ‘class Nan::Persistent<v8::Object>’ has no member named ‘IsNearDeath’
     assert(wrap->handle_.IsNearDeath());
                          ^
binding.target.mk:127: recipe for target 'Release/obj.target/binding/src/binding.o' failed
make: *** [Release/obj.target/binding/src/binding.o] Error 1
make: Leaving directory '/home/travis/build/mycolorway/tower/node_modules/node-sass/build'
gyp ERR! build error 
gyp ERR! stack Error: `make` failed with exit code: 2
gyp ERR! stack     at ChildProcess.onExit (/home/travis/build/mycolorway/tower/node_modules/node-gyp/lib/build.js:262:23)
gyp ERR! stack     at ChildProcess.emit (events.js:196:13)
gyp ERR! stack     at Process.ChildProcess._handle.onexit (internal/child_process.js:256:12)
gyp ERR! System Linux 4.15.0-1028-gcp
gyp ERR! command "/home/travis/.nvm/versions/node/v12.0.0/bin/node" "/home/travis/build/mycolorway/tower/node_modules/node-gyp/bin/node-gyp.js" "rebuild" "--verbose" "--libsass_ext=" "--libsass_cflags=" "--libsass_ldflags=" "--libsass_library="
gyp ERR! cwd /home/travis/build/mycolorway/tower/node_modules/node-sass
gyp ERR! node -v v12.0.0
gyp ERR! node-gyp -v v3.8.0
gyp ERR! not ok 
Build failed with error code: 1
info Visit https://yarnpkg.com/en/docs/cli/install for documentation about this command.
The command "yarn install" failed and exited with 1 during .
Your build has been stopped.
```