Install mysql2 with mysql installed via brew on MacOS High Sierra

msql2

````
gem install mysql2 -v 'YOUR.VERSION.HERE' -- --with-mysql-config=/usr/local/opt/mysql-client/bin/mysql_config \
                 --srcdir=/usr/local/opt/mysql/include --platform=ruby \
                 --with-ldflags=-L/usr/local/opt/openssl/lib \
                 --with-cppflags=-I/usr/local/opt/openssl/include
```                 
                 
On Mojave, High Sierra, or Catalina, using homebrew.

https://gist.github.com/fernandoaleman/ee3ac6957c2ba4f7d7d33a251d58b191#gistcomment-2910891