* Add isort_code.sh to sanity tests
* Run tools/distrib/isort_code.sh
* Fine tune the import order for relative imports
* Make pylint and project generation happy
* Fix a few corner cases
* Use --check instead of --diff
* The import order impacts test result somehow
* Make isort print diff and check output at the same time
* Let tools/run_tests/python_utils be firstparty library
* Run isort against latest HEAD
* Use latest pylint in Python 3.7 (they dropped support for PY2)
* Make latest pylint happy
* Forced to upgrade to shellcheck 0.4.4
* Make shellcheck 0.4.4 happy
* Adopt reviewers' advice to reduce global disabled rules
The source code is moved from src/python to
src/python/src. A setup.py is added at
src/python. The build_python.sh and
run_python.sh scripts are updated to build
and run the Python tests by building a
package and installing it in the developer's
Python 2.7 virtual environment.