Adds docker support for all the executables

[leandromoreira]

fixes #32

[li-zhi]

@leandromoreira I am also editing the README a bit.

[leandromoreira]

That's fine, English is not my native language, also is there a way to know what is each model of the folder https://github.com/Netflix/vmaf/tree/master/resource/model ? (I mean what is trained model most of the people can use... [probably the one you trained with netflix+non-netflix videos] )

[li-zhi]

Please see
https://github.com/Netflix/vmaf/blob/master/python/core/quality_runner.py#L254
For VMAF v.0.3.2, the model should be nflxall_vmafv4.pkl. Apologize for not keeping the version numbers in sync. Will do that in the future. I will add this to README file also.