Example: reg diagnostics
COMPAT: Python 3 fix. Closes #1055.
COMPAT: Allow 3.x cached files to be opened in 2.x
Merge pull request #1057 from jseabold/fix-py3-caching

COMPAT: Fix py3 caching for get_rdatasets.
Merge pull request #1056 from vincentarelbundock/example_regression_diagnostics

Example: reg diagnostics
notebook examples title cell
Merge pull request #1072 from vincentarelbundock/notebook_fix

notebook examples title cell
ENH: Initial changes to enable coveralls.io support
DOC: very minor (trailing spaces) to trigger travis build
BF: coveralls -- fix up the order of commands and comparison to current version (travis language is not python here)
BF: install coverage through pip as well (since we are not lang python -- coverage is not there)
yarik wants to see why sudo is needed to run tests (and trigger a new build)
BF: forgotten fix to use PYSUF for comparison
uff -- pip install failed, so removing -q and splitting into separate calls for coverage and coveralls
coverage must be installed with sudo
BF: no sudo for easy_install and pip!
BF: grr -- sudo is needed in this setup although it should not be needed -- adding back for easy_install and pip
BF: remember the original directory with sources -- and cd back there for tests and coveralls

otherwise coveralls doesn't find the repository: https://travis-ci.org/yarikoptic/pystatsmodels/jobs/11293375
Fixing up yaml
Output PWD few times to figure out where/what is happening and run tests under travis-test directory