move dev only gems into dev group

Gemfile

@@ -130,14 +130,29 @@ group :development, :test do
   # for security audit'
   gem 'brakeman', '~> 2.6.2', require: false
 
-  # Spring speeds up development by keeping your application running in the background.
-  # Read more: https://github.com/rails/spring
-  # gem 'spring', '~> 1.2.0'
-  # gem 'spring-commands-rspec', '~> 1.0.2'
-
   # bundle exec rake doc:rails generates the API under doc/api.
   gem 'sdoc', '~> 0.4.0'
 
+  # faster dev load time
+  gem 'unicorn'
+end
+
+group :development do
+  # Spring speeds up development by keeping your application running in the background.
+  # Read more: https://github.com/rails/spring
+  gem 'spring', '~> 1.2.0'
+  gem 'spring-commands-rspec', '~> 1.0.2'
+
+  # for fast deployment
+  gem 'mina', '~> 0.3.1'
+
+  # for finding dead routes and unused actions
+  gem 'traceroute', '~> 0.4.0'
+
+  # for improved errors
+  gem 'better_errors', '~> 2.0.0'
+  gem 'binding_of_caller', '~> 0.7.2'
+
   # run tests automatically
   gem 'guard', '~> 2.6.1'
 
@@ -145,17 +160,5 @@ group :development, :test do
   gem 'guard-rspec', '~> 4.3.1'
   gem 'rubocop', '~> 0.26.1'
   gem 'guard-rubocop', '~> 1.1.0'
-
-  # for improved errors
-  gem 'better_errors', '~> 2.0.0'
-  gem 'binding_of_caller', '~> 0.7.2'
-
-  # for finding dead routes and unused actions
-  gem 'traceroute', '~> 0.4.0'
-
-  # faster dev load time
-  gem 'unicorn'
-
-  # for fast deployment
-  gem 'mina', '~> 0.3.1'
 end
+

Gemfile.lock

@@ -309,6 +309,9 @@ GEM
       temple (~> 0.6.6)
       tilt (>= 1.3.3, < 2.1)
     slop (3.6.0)
+    spring (1.2.0)
+    spring-commands-rspec (1.0.2)
+      spring (>= 0.9.1)
     sprockets (2.8.0)
       hike (~> 1.2)
       multi_json (~> 1.0)
@@ -412,6 +415,8 @@ DEPENDENCIES
   shoulda-matchers (~> 2.6.1)
   simplecov (~> 0.9.1)
   simpleidn (~> 0.0.5)
+  spring (~> 1.2.0)
+  spring-commands-rspec (~> 1.0.2)
   therubyracer
   traceroute (~> 0.4.0)
   turbolinks