title: Postgresql gem install pg 0.18.4 passes, bundle install fails
body: <p>Mac OS El Capitan</p>
  
  <p>Bundle install fails with:</p>
  
  <pre><code>compiling pg_connection.c
  pg_connection.c:2394:3: warning: implicit declaration of function 'gettimeofday' is invalid in C99 [-Wimplicit-function-declaration]
                  gettimeofday(&amp;currtime, NULL);
                  ^
  1 warning generated.
  compiling pg_copy_coder.c
  compiling pg_errors.c
  compiling pg_result.c
  compiling pg_text_decoder.c
  compiling pg_text_encoder.c
  compiling pg_type_map.c
  compiling pg_type_map_all_strings.c
  compiling pg_type_map_by_class.c
  compiling pg_type_map_by_column.c
  compiling pg_type_map_by_mri_type.c
  compiling pg_type_map_by_oid.c
  compiling pg_type_map_in_ruby.c
  compiling util.c
  linking shared-object pg_ext.bundle
  ld: file not found: dynamic_lookup
  clang: error: linker command failed with exit code 1 (use -v to see invocation)
  make: *** [pg_ext.bundle] Error 1
  
  make failed, exit code 2
  
  Gem files will remain installed in /Users/jmintz/Documents/LaunchAngels/radar/vendor/bundle/gems/pg-0.18.4 for inspection.
  Results logged to /Users/jmintz/Documents/LaunchAngels/radar/vendor/bundle/extensions/x86_64-darwin-15/2.2.0-static/pg-0.18.4/gem_make.out
  </code></pre>
  
  <p>...
  ...  </p>
  
  <pre><code>An error occurred while installing pg (0.18.4), and Bundler cannot continue.
  
  Make sure that `gem install pg -v '0.18.4'` succeeds before bundling.
  </code></pre>
  
  <p>Running 'gem install pg -v '0.18.4' results in:</p>
  
  <pre><code>Building native extensions.  This could take a while...
  Successfully installed pg-0.18.4
  Parsing documentation for pg-0.18.4
  Done installing documentation for pg after 4 seconds
  1 gem installed
  </code></pre>
  
  <p>Yet running 'bundle install' again fails. Any suggestions? I've tried uninstalling and reinstalling postgresql with homebrew with no luck</p>