Update RuboCop to 0.43.0 and update configuration

`Style/VariableNumber` is explicitly disabled because I don't think we
care if we name a variable `var_1` or `var1`.

.rubocop.yml

@@ -453,6 +453,10 @@ Style/VariableName:
   EnforcedStyle: snake_case
   Enabled: true
 
+# Use the configured style when numbering variables.
+Style/VariableNumber:
+  Enabled: false
+
 # Use when x then ... for one-line cases.
 Style/WhenThen:
   Enabled: true

Gemfile

@@ -295,7 +295,7 @@ group :development, :test do
   gem 'spring-commands-spinach',  '~> 1.1.0'
   gem 'spring-commands-teaspoon', '~> 0.0.2'
 
-  gem 'rubocop', '~> 0.42.0', require: false
+  gem 'rubocop', '~> 0.43.0', require: false
   gem 'rubocop-rspec', '~> 1.5.0', require: false
   gem 'scss_lint', '~> 0.47.0', require: false
   gem 'haml_lint', '~> 0.18.2', require: false

Gemfile.lock

@@ -487,7 +487,7 @@ GEM
     orm_adapter (0.5.0)
     paranoia (2.1.4)
       activerecord (~> 4.0)
-    parser (2.3.1.2)
+    parser (2.3.1.4)
       ast (~> 2.2)
     pg (0.18.4)
     pkg-config (1.1.7)
@@ -620,7 +620,7 @@ GEM
     rspec-retry (0.4.5)
       rspec-core
     rspec-support (3.5.0)
-    rubocop (0.42.0)
+    rubocop (0.43.0)
       parser (>= 2.3.1.1, < 3.0)
       powerpack (~> 0.1)
       rainbow (>= 1.99.1, < 3.0)
@@ -938,7 +938,7 @@ DEPENDENCIES
   rqrcode-rails3 (~> 0.1.7)
   rspec-rails (~> 3.5.0)
   rspec-retry (~> 0.4.5)
-  rubocop (~> 0.42.0)
+  rubocop (~> 0.43.0)
   rubocop-rspec (~> 1.5.0)
   ruby-fogbugz (~> 0.2.1)
   ruby-prof (~> 0.16.2)