move _codelinesAsString from parsons object to graders
Merge branch 'master' of github.com:vkaravir/js-parsons into codelinesAsString-refactor

* 'master' of github.com:vkaravir/js-parsons:
  Added example of the variable grader
bug fixing
remove unused code
Merge pull request #9 from vkaravir/codelinesAsString-refactor

Codelines as string refactor