Started implementation of Javascript Evaluator

signed-off-by: Alessandro Palmeira <alessandro.palmeira@gmail.com>
[Evaluator] Created InvalidIdentifier error.

signed-off-by: Alessandro Palmeira <alessandro.palmeira@gmail.com>
[Evaluator] Add_variable method.

signed-off-by: Alessandro Palmeira <alessandro.palmeira@gmail.com>
[Evaluator] validate_identifier method is now private
JavaScriptEvaluator#add_function

Signed off by: Alessandro Palmeira <alessandro.palmeira@gmail.com>
Evaluate for Javascript

Signed off by: Alessandro Palmeira <alessandro.palmeira@gmail.com>
Refactored CompoundResultsCalculator module name to CompoundResults

Signed off by: Alessandro Palmeira <alessandro.palmeira@gmail.com>
CompoundResults::Calculator
CompoundMetric Calculator

Signed off by: Diego Araújo <diegoamc90@gmail.com>