Add CONTRIBUTING.md
Fix Travis integration config option in .coveralls.yml.

"Another important option is service_name which allows you to specify where Coveralls should look to find additional information about your builds. This can be any string, but using travis-ci or travis-pro will allow Coveralls to fetch branch data, comment on pull requests, and more."
Add MIT license.
Merge pull request #17 from coursemology-collab/lowjoel/fix-coveralls-travis-config

Fix Travis integration config option in .coveralls.yml.
Merge pull request #16 from jsyeo/jsyeo-contributing

Add CONTRIBUTING.md
Merge pull request #18 from jsyeo/jsyeo-license

Add MIT license
implement user role
implement role in instance_user
test cases for user role & refine exsiting tests
set role in factories
tests for instance role(pending)
comment out enum field and use numbers for now
add spaces after # as hound suggested
update schema validations gem
update user model specs
reorder role columns in schema file
course model specs
implement course model according to specs
enrolment specs
implement enrolment model