Bug fixes and other changes
* enable line-too-long Pylint check
* improving Chainer integ tests
* update TensorFlow script mode dependency list
* improve documentation of some functions
* update PyTorch version
* allow serving script to be defined for deploy() and transformer() with frameworks
* format and add missing docstring placeholders
* add MXNet 1.4.1 support
Documentation changes
* add instructions for setting up Cloud9 environment.
* update using_tensorflow topic