Fix rubocop warnings

lib/mutant/cli/classifier.rb

@@ -44,11 +44,9 @@ module Mutant
       # @api private
       #
       def self.constant_lookup(location)
-        location
-          .sub(CBASE_PATTERN, EMPTY_STRING)
-          .split(SCOPE_OPERATOR)
+        location.sub(CBASE_PATTERN, EMPTY_STRING).split(SCOPE_OPERATOR)
           .reduce(Object) do |parent, name|
-            parent.const_get(name, nil)
+          parent.const_get(name, nil)
         end
       end
 

lib/mutant/differ.rb

@@ -16,16 +16,12 @@ module Mutant
     # @api private
     #
     def diff
-      output = ''
       case diffs.length
       when 0
         nil
       when 1
-        output =
-          Diff::LCS::Hunk.new(
-            old, new, diffs.first, max_length, 0
-          ).diff(:unified)
-        output << "\n"
+        Diff::LCS::Hunk.new(old, new, diffs.first, max_length, 0)
+          .diff(:unified) << "\n"
       else
         $stderr.puts(
           'Mutation resulted in more than one diff, should not happen! ' +

spec/unit/mutant/cli/classifier/namespace/flat_spec.rb

@@ -32,7 +32,7 @@ describe Mutant::CLI::Classifier::Namespace::Flat, '#each' do
   end
 
   context 'without a block' do
-   subject { object.each }
+    subject { object.each }
 
     context 'with a known namespace' do
       let(:input) { known_namespace }

spec/unit/mutant/cli/classifier/namespace/recursive_spec.rb

@@ -32,7 +32,7 @@ describe Mutant::CLI::Classifier::Namespace::Recursive, '#each' do
   end
 
   context 'without a block' do
-   subject { object.each }
+    subject { object.each }
 
     context 'with a known namespace' do
       let(:input) { known_namespace }

spec/unit/mutant/strategy_spec.rb

@@ -20,4 +20,3 @@ describe Mutant::Strategy do
     it_should_behave_like 'a command method'
   end
 end
-