* [Docs] Add header for files * change to OpenMMLab * add headers for .cpp, .cu, .h, .cuh * replace Open-MMLab with OpenMMLab
* add copyright header * change # to // for cpp files
* 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