nokogiriをいれた後のbunlde install .md

$ bundle install
Fetching gem metadata from https://rubygems.org/.........
Using rake 10.3.2
Using i18n 0.6.11
Using minitest 4.7.5
Using multi_json 1.10.1
Using thread_safe 0.3.4
Using tzinfo 0.3.40
Using activesupport 4.0.8
Using builder 3.1.4
Using erubis 2.7.0
Using rack 1.5.2
Using rack-test 0.6.2
Using actionpack 4.0.8
Using mime-types 1.25.1
Using polyglot 0.3.5
Using treetop 1.4.15
Using mail 2.5.4
Using actionmailer 4.0.8
Using activemodel 4.0.8
Using activerecord-deprecated_finders 1.0.3
Using arel 4.0.2
Using activerecord 4.0.8
Using bcrypt-ruby 3.1.2
Using sass 3.3.10
Using bootstrap-sass 2.3.2.0
Using will_paginate 3.0.4
Using bootstrap-will_paginate 0.0.9
Using mini_portile 0.6.0
Building nokogiri using system libraries.
Installing nokogiri 1.6.2.1
Installing xpath 2.0.0
Installing capybara 2.1.0
Installing hitimes 1.2.2
Installing timers 4.0.1
Installing celluloid 0.16.0
Installing ffi 1.9.5
Installing childprocess 0.3.6
Installing coderay 1.1.0
Installing coffee-script-source 1.7.1
Installing execjs 2.2.1
Installing coffee-script 2.3.0
Using thor 0.19.1
Installing railties 4.0.8
Installing coffee-rails 4.0.1
Installing diff-lcs 1.2.5
Installing gherkin 2.12.2
Installing multi_test 0.1.1
Installing cucumber 1.3.16
Using bundler 1.7.4
Using hike 1.2.3
Using tilt 1.4.1
Installing sprockets 2.11.0
Installing sprockets-rails 2.0.1
Installing rails 4.0.8
Installing cucumber-rails 1.4.0
Using database_cleaner 1.3.0 from git://github.com/bmabey/database_cleaner.git (at master)
Installing factory_girl 4.2.0
Installing factory_girl_rails 4.2.0
Installing faker 1.1.2
Installing formatador 0.2.5
Installing rb-fsevent 0.9.4
Installing rb-inotify 0.9.5
Installing listen 2.7.11
Installing lumberjack 1.0.9
Installing method_source 0.8.2
Installing slop 3.6.0
Installing pry 0.10.1
Installing guard 2.6.1
Installing rspec-core 2.13.1
Installing rspec-expectations 2.13.0
Installing rspec-mocks 2.13.1
Installing rspec 2.13.0
Installing guard-rspec 2.5.0
Installing spork 1.0.0rc4
Installing guard-spork 1.5.0
Installing jbuilder 1.0.2
Installing jquery-rails 3.0.4
Using json 1.8.1

Gem::Ext::BuildError: ERROR: Failed to build gem native extension.

    /home/vagrant/.rbenv/versions/2.1.4/bin/ruby -r ./siteconf20141107-5213-18m62pu.rb extconf.rb
checking for pg_config... no
No pg_config... trying anyway. If building fails, please try again with
 --with-pg-config=/path/to/pg_config
checking for libpq-fe.h... no
Can't find the 'libpq-fe.h header
*** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of necessary
libraries and/or headers.  Check the mkmf.log file for more details.  You may
need configuration options.

Provided configuration options:
	--with-opt-dir
	--without-opt-dir
	--with-opt-include
	--without-opt-include=${opt-dir}/include
	--with-opt-lib
	--without-opt-lib=${opt-dir}/lib
	--with-make-prog
	--without-make-prog
	--srcdir=.
	--curdir
	--ruby=/home/vagrant/.rbenv/versions/2.1.4/bin/ruby
	--with-pg
	--without-pg
	--with-pg-dir
	--without-pg-dir
	--with-pg-include
	--without-pg-include=${pg-dir}/include
	--with-pg-lib
	--without-pg-lib=${pg-dir}/lib
	--with-pg-config
	--without-pg-config
		--with-pg_config
	--without-pg_config

extconf failed, exit code 1

Gem files will remain installed in /home/vagrant/.rbenv/versions/2.1.4/lib/ruby/gems/2.1.0/gems/pg-0.15.1 for inspection.
Results logged to /home/vagrant/.rbenv/versions/2.1.4/lib/ruby/gems/2.1.0/extensions/x86_64-linux/2.1.0-static/pg-0.15.1/gem_make.out
An error occurred while installing pg (0.15.1), and Bundler cannot continue.
Make sure that `gem install pg -v '0.15.1'` succeeds before bundling.