Update README.md
Merge pull request #31 from antonagestam/contribution

Note about contribution …
document cache behaviour

fixes #17
Merge pull request #32 from antonagestam/document-caching

Document cache behaviour

Thank you for the help @erikcw :cake:
cleanup
added test structure and test runner
fix input for 1.4 + cleanup + separation of concerns
wrote majority of tests
testing testing testing ...
check not None
hash
tests, requirements, +x
test structure
travis setup
test setup