Set up continuous integration
Set up continuous integration

For every push and pull request to master:
- (installs necessary pip requirements)
- run test cases with pytest (any file with the word "test" in it)
- check types with pytype

Note: we don't run through pylint here, because its configurations for
tabs and spaces are double of the requirements for gpylint, which will
causes many errors that shouldn't be errors.

googleinterns/acuiti