add pg gem

Gemfile

@@ -11,8 +11,9 @@ end
 gem "rails", "3.2.8"
 
 # Supported DBs
-gem "sqlite3"
-gem "mysql2"
+gem "sqlite3", :group => :sqlite
+gem "mysql2", :group => :mysql
+gem "pg", :group => :postgres
 
 # Auth
 gem "devise", "~> 2.1.0"

Gemfile.lock

@@ -245,6 +245,7 @@ GEM
       multi_json (~> 1.3)
       omniauth-oauth (~> 1.0)
     orm_adapter (0.3.0)
+    pg (0.14.0)
     polyglot (0.3.3)
     posix-spawn (0.3.6)
     pry (0.9.9.6)
@@ -441,6 +442,7 @@ DEPENDENCIES
   omniauth-google-oauth2
   omniauth-ldap!
   omniauth-twitter
+  pg
   pry
   pygments.rb (= 0.3.1)
   rack-mini-profiler