Bump spring

Gemfile

@@ -249,7 +249,7 @@ group :development do
 
   # Preloading environment
 
-  gem "spring", "1.7.2"
+  gem "spring", "2.0.0"
   gem "spring-commands-rspec", "1.0.4"
   gem "spring-commands-cucumber", "1.0.1"
 

Gemfile.lock

@@ -809,7 +809,8 @@ GEM
     sinon-rails (1.15.0)
       railties (>= 3.1)
     slop (3.6.0)
-    spring (1.7.2)
+    spring (2.0.0)
+      activesupport (>= 4.2)
     spring-commands-cucumber (1.0.1)
       spring (>= 0.9.1)
     spring-commands-rspec (1.0.4)
@@ -1035,7 +1036,7 @@ DEPENDENCIES
   simplecov (= 0.12.0)
   sinatra (= 1.4.7)
   sinon-rails (= 1.15.0)
-  spring (= 1.7.2)
+  spring (= 2.0.0)
   spring-commands-cucumber (= 1.0.1)
   spring-commands-rspec (= 1.0.4)
   test_after_commit (= 1.1.0)