## What do these changes do?
1. Separate the log related code to logger.py from services.py.
2. Allow users to modify logging formatter in `ray start`.
## Related issue number
https://github.com/ray-project/ray/pull/2664
* Add flake8 to Travis
* Add flake8-comprehensions
[flake8 plugin](https://github.com/adamchainz/flake8-comprehensions) that
checks for useless constructions.
* Use generators instead of lists where appropriate
A lot of the builtins can take in generators instead of lists.
This commit applies `flake8-comprehensions` to find them.
* Fix lint error
* Fix some string formatting
The rest can be fixed in another PR
* Fix compound literals syntax
This should probably be merged after #1963.
* dict() -> {}
* Use dict literal syntax
dict(...) -> {...}
* Rewrite nested dicts
* Fix hanging indent
* Add missing import
* Add missing quote
* fmt
* Add missing whitespace
* rm duplicate pip install
This is already installed in another file.
* Fix indent
* move `merge_dicts` into utils
* Bring up to date with `master`
* Add automatic syntax upgrade
* rm pyupgrade
In case users want to still use it on their own, the upgrade-syn.sh script was
left in the `.travis` dir.
* Add basic functionality for Cython functions and actors
* Fix up per @pcmoritz comments
* Fixes per @richardliaw comments
* Fixes per @robertnishihara comments
* Forgot double quotes when updating masked_log
* Remove import typing for Python 2 compatibility
* 4 space indentation for actor.py.
* 4 space indentation for worker.py.
* 4 space indentation for more files.
* 4 space indentation for some test files.
* Check indentation in Travis.
* 4 space indentation for some rl files.
* Fix failure test.
* Fix multi_node_test.
* 4 space indentation for more files.
* 4 space indentation for remaining files.
* Fixes.
