diff --git a/.ruby-version b/.ruby-version
new file mode 100644
index 0000000000..437459cd94
--- /dev/null
+++ b/.ruby-version
@@ -0,0 +1 @@
+2.5.0
diff --git a/Gemfile b/Gemfile
index a48e8e62a4..132333fef4 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,10 +1,10 @@
 source 'https://rubygems.org'
 
-ruby '2.4.0'
-
 gem 'rake'
-gem 'reek'
-gem 'rspec'
 gem 'rubocop'
-gem 'simplecov', require: false, group: :test
-gem 'simplecov-console', require: false, group: :test
+
+group :test do
+  gem 'rspec'
+  gem 'simplecov', require: false
+  gem 'simplecov-console', require: false
+end
diff --git a/Gemfile.lock b/Gemfile.lock
index 8cc9233be8..3b07d9c913 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -3,81 +3,57 @@ GEM
   specs:
     ansi (1.5.0)
     ast (2.3.0)
-    axiom-types (0.1.1)
-      descendants_tracker (~> 0.0.4)
-      ice_nine (~> 0.11.0)
-      thread_safe (~> 0.3, >= 0.3.1)
-    codeclimate-engine-rb (0.4.0)
-      virtus (~> 1.0)
-    coercible (1.0.0)
-      descendants_tracker (~> 0.0.1)
-    descendants_tracker (0.0.4)
-      thread_safe (~> 0.3, >= 0.3.1)
     diff-lcs (1.3)
     docile (1.1.5)
-    equalizer (0.0.11)
     hirb (0.7.3)
-    ice_nine (0.11.2)
-    json (2.0.4)
-    parser (2.4.0.0)
-      ast (~> 2.2)
+    json (2.1.0)
+    parallel (1.12.1)
+    parser (2.4.0.2)
+      ast (~> 2.3)
     powerpack (0.1.1)
-    rainbow (2.2.1)
-    rake (12.0.0)
-    reek (4.6.1)
-      codeclimate-engine-rb (~> 0.4.0)
-      parser (>= 2.3.1.2, < 2.5)
-      rainbow (~> 2.0)
-    rspec (3.5.0)
-      rspec-core (~> 3.5.0)
-      rspec-expectations (~> 3.5.0)
-      rspec-mocks (~> 3.5.0)
-    rspec-core (3.5.4)
-      rspec-support (~> 3.5.0)
-    rspec-expectations (3.5.0)
+    rainbow (3.0.0)
+    rake (12.3.0)
+    rspec (3.7.0)
+      rspec-core (~> 3.7.0)
+      rspec-expectations (~> 3.7.0)
+      rspec-mocks (~> 3.7.0)
+    rspec-core (3.7.1)
+      rspec-support (~> 3.7.0)
+    rspec-expectations (3.7.0)
       diff-lcs (>= 1.2.0, < 2.0)
-      rspec-support (~> 3.5.0)
-    rspec-mocks (3.5.0)
+      rspec-support (~> 3.7.0)
+    rspec-mocks (3.7.0)
       diff-lcs (>= 1.2.0, < 2.0)
-      rspec-support (~> 3.5.0)
-    rspec-support (3.5.0)
-    rubocop (0.48.1)
-      parser (>= 2.3.3.1, < 3.0)
+      rspec-support (~> 3.7.0)
+    rspec-support (3.7.0)
+    rubocop (0.52.1)
+      parallel (~> 1.10)
+      parser (>= 2.4.0.2, < 3.0)
       powerpack (~> 0.1)
-      rainbow (>= 1.99.1, < 3.0)
+      rainbow (>= 2.2.2, < 4.0)
       ruby-progressbar (~> 1.7)
       unicode-display_width (~> 1.0, >= 1.0.1)
-    ruby-progressbar (1.8.1)
-    simplecov (0.14.1)
+    ruby-progressbar (1.9.0)
+    simplecov (0.15.1)
       docile (~> 1.1.0)
       json (>= 1.8, < 3)
       simplecov-html (~> 0.10.0)
-    simplecov-console (0.4.1)
+    simplecov-console (0.4.2)
       ansi
       hirb
       simplecov
-    simplecov-html (0.10.0)
-    thread_safe (0.3.6)
-    unicode-display_width (1.2.1)
-    virtus (1.0.5)
-      axiom-types (~> 0.1)
-      coercible (~> 1.0)
-      descendants_tracker (~> 0.0, >= 0.0.3)
-      equalizer (~> 0.0, >= 0.0.9)
+    simplecov-html (0.10.2)
+    unicode-display_width (1.3.0)
 
 PLATFORMS
   ruby
 
 DEPENDENCIES
   rake
-  reek
   rspec
   rubocop
   simplecov
   simplecov-console
 
-RUBY VERSION
-   ruby 2.4.0p0
-
 BUNDLED WITH
-   1.14.0
+   1.16.0