Modify setup.py handling

[mbeacom]

The goal of this PR is to implement changes to setup.py to include:

• Installation extras option: optional to install all optional dependencies via pip.
• Installation extras option: test to install all test dependencies via pip.
• Installation extras option: docs to install all documentation dependencies via pip.
• Classification changes/additions.
• Add PyTest setup.py command, to enable python setup.py test to install testing dependencies and run testing suite.
• Add Sphinx BuildDoc setup.py command, to enable python setup.py build_doc to build HTML documentation.

Simple additions to documentation:

• Running the test suite.
• Building the documentation.
• Installing all optional requirements via pip.
• Installing all documentation-building requirements via pip.
• Installing all test requirements via pip.

Misc modifications:

• Add shell env type specification header to makehtml.sh to make it executable.
• Change documentation build structure to build inside of the repo directory at: ./docs/build/ and simply ignore the build directory.

Steps to test

• Assert that python setup.py test successfully installs the moviepy test dependencies and runs the test suite.
• Assert that pip install -e .[docs]; python setup.py build_docs -E; open docs/build/html/index.html successfully installs the moviepy doc dependencies and builds the documentation.
• Assert that pip install -e .[optional] successfully installs all of the moviepy dependencies.
• Assert that pip install -e .[test] successfully installs all of test related moviepy dependencies.
• Assert that pip install -e . successfully installs moviepy base.

[coveralls]

Coverage remained the same at 50.282% when pulling c6fec68 on mbeacom:dev-reqs-setup into b76beb4 on Zulko:master.

[ghost]

this is a bit beyond my current skill level, but it looks good to me.

[ghost]

looks good to me.

[Zulko]

To me too. I just hope it doesn't complicate installation via other means than pip, but it doesn't seem so.

[coveralls]

Coverage remained the same at 53.104% when pulling edfc8bb on mbeacom:dev-reqs-setup into 7216089 on Zulko:master.

[coveralls]

Coverage remained the same at 53.104% when pulling edfc8bb on mbeacom:dev-reqs-setup into 7216089 on Zulko:master.

[coveralls]

Coverage remained the same at 53.104% when pulling edfc8bb on mbeacom:dev-reqs-setup into 7216089 on Zulko:master.

[coveralls]

Coverage remained the same at 53.104% when pulling 7a3cc62 on mbeacom:dev-reqs-setup into 7216089 on Zulko:master.