GitLab

* add macos in github action

* fix a package name

* minor fix

* fix typo

* ignore progressbar testing

* ignore timer testing

* fix pytest configs

* try fix

* add yapf for pretty text

* add yapf style

* remove supports for python 2.7

* fix the unit test for python 3.5

* add python 3.8 in CI

* try ubuntu 18.04 as the environment

* add copyright header

* change # to // for cpp files

* add pre-commit hooks

* update yapf version

* add yapf and isort to travis

* minor formatting

* remove blank lines

* skip unit tests for progressbar when python2

* update travis to ubuntu 16.04

* use a newer version ffmpeg

* add -y to add-apt-repository