Update dev dependencies with security issues

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Gemfile

@@ -7,5 +7,5 @@ group :development, :test do
   gem 'guard'
   gem 'guard-rspec'
   gem 'vcr'
-  gem 'rubocop', '0.28.0', require: false
+  gem 'rubocop', '0.49.1', require: false
 end

Gemfile.lock

@@ -2,11 +2,9 @@ GEM
   remote: http://rubygems.org/
   specs:
     addressable (2.3.2)
-    ast (2.0.0)
-    astrolabe (1.3.0)
-      parser (>= 2.2.0.pre.3, < 3.0)
+    ast (2.4.0)
     coderay (1.0.8)
-    crack (0.3.1)
+    crack (0.3.2)
     diff-lcs (1.2.5)
     docile (1.1.5)
     guard (1.5.4)
@@ -21,14 +19,17 @@ GEM
     lumberjack (1.0.2)
     method_source (0.8.1)
     multi_json (1.10.1)
-    parser (2.2.0.2)
-      ast (>= 1.1, < 3.0)
-    powerpack (0.0.9)
+    parallel (1.12.1)
+    parser (2.5.0.2)
+      ast (~> 2.4.0)
+    powerpack (0.1.1)
     pry (0.9.10)
       coderay (~> 1.0.5)
       method_source (~> 0.8)
       slop (~> 3.3.1)
-    rainbow (2.0.0)
+    rainbow (2.2.2)
+      rake
+    rake (12.3.0)
     rspec (2.14.1)
       rspec-core (~> 2.14.0)
       rspec-expectations (~> 2.14.0)
@@ -37,13 +38,14 @@ GEM
     rspec-expectations (2.14.5)
       diff-lcs (>= 1.1.3, < 2.0)
     rspec-mocks (2.14.6)
-    rubocop (0.28.0)
-      astrolabe (~> 1.3)
-      parser (>= 2.2.0.pre.7, < 3.0)
-      powerpack (~> 0.0.6)
+    rubocop (0.49.1)
+      parallel (~> 1.10)
+      parser (>= 2.3.3.1, < 3.0)
+      powerpack (~> 0.1)
       rainbow (>= 1.99.1, < 3.0)
-      ruby-progressbar (~> 1.4)
-    ruby-progressbar (1.7.1)
+      ruby-progressbar (~> 1.7)
+      unicode-display_width (~> 1.0, >= 1.0.1)
+    ruby-progressbar (1.9.0)
     simplecov (0.9.1)
       docile (~> 1.1.0)
       multi_json (~> 1.0)
@@ -51,6 +53,7 @@ GEM
     simplecov-html (0.8.0)
     slop (3.3.3)
     thor (0.19.1)
+    unicode-display_width (1.3.0)
     vcr (2.4.0)
     webmock (1.9.0)
       addressable (>= 2.2.7)
@@ -63,7 +66,7 @@ DEPENDENCIES
   guard
   guard-rspec
   rspec (~> 2.14.0)
-  rubocop (= 0.28.0)
+  rubocop (= 0.49.1)
   simplecov
   vcr
   webmock