add coffee-script to package.json
fix npm scripts `build` and `test`
fix typo cottent => content
Merge branch 'feature/fix_typo' into develop
fix typo in collection constructor
Merge branch 'feature/fix_typo_collection_constructor' into develop
add addCollection method
Merge pull request #6 from muddydixon/feature/add_addCollection_method

Feature/add add collection method