The sqlite3 gem is moved to dev and test only

Gemfile

@@ -68,7 +68,6 @@ gem 'twitter'
 
 group :development do
   gem 'quiet_assets'
-  gem 'sqlite3'
   gem 'webrick'
 
   # Access an IRB console on exception pages or by using <%= console %> in views
@@ -99,9 +98,7 @@ group :test do
 end
 
 group :development, :test do
-  # Spring speeds up development by keeping your application running in the
-  # background. Read more: https://github.com/rails/spring
-  gem 'spring'
+  gem 'sqlite3'
 end
 
 group :development, :test, :assets do
@@ -138,6 +135,8 @@ group :assets do
 end
 
 group :production do
+  # Use postgresql as the database for Active Record
+  # gem 'pg'
   # Use mysql as the database for Active Record
   gem 'mysql2'
 end

Gemfile.lock

@@ -365,8 +365,6 @@ GEM
       simplecov-html (~> 0.10.0)
     simplecov-html (0.10.0)
     slop (3.6.0)
-    spring (2.0.1)
-      activesupport (>= 4.2)
     sprockets (3.7.1)
       concurrent-ruby (~> 1.0)
       rack (> 1, < 3)
@@ -469,7 +467,6 @@ DEPENDENCIES
   sdoc
   simple_calendar
   simplecov
-  spring
   sqlite3
   strip_attributes
   tagsinput-rails