Start to move mutator logic into separate component.
Pass the first couple of features for the mutator component.
Allow configuration of specific mutation operator in mutator component.
Add BinaryArithmeticOperatorReplacement mutation operator.
Rename original mutation operator to RelationalOperatorReplacement.
Update todo list.
Added regression test for RelationalOperatorReplacement.
Updated todo list.
Added ConditionalOperatorReplacement mutation operator.
Update todo list.
Add ShortcutAssignmentOperatorReplacement mutation operator.
Added logical operator replacement.
Added ReplaceRelationalExpression mutation operator.
Added UnaryArthimeticOperatorReplacement mutation operator.
Extracted mutation operator registry.
Update todo list.
Updated dependencies.
Upgrade to Ruby 2.1.1.