Consolidating separating individual modules into their packages

[anujkumar93]

@jtratner

This PR handles actually separating the repo into individual packages of stor, stor_s3, stor_swift, stor_dx.

Background

This is a continuation of (and maybe the end of) the story to split stor across 4 modules : stor, stor_dx, stor_swift, stor_s3. This is done to easy the dependencies that need to be installed to use a particular fact of stor, and to make it more modular. This PR is preceded by anujkumar93#10 for this story.

Changes

This PR handles the actual separation of modules into three different packages.

• The first commit just moves the files around, each module into their own nested package.

• The second commit is responsible for setting up the setup.py, setup.cfg, requirements.txt, etc for the individual packages, and changing makefile, tox.ini to get this separation into a working state. The key function find_cls_for_pth in init.py and its tests are implemented in this commit.

• The rest of the commits address the review comments and bug/lint fixes, making travis-test work, refining sdist packaging functions in Makefile, etc.

• Release notes and docs

• Addressed Preparing the modules to be split #100 (comment)

Tested via:

The testing suite was run after adding tests for find_cls_for_pth (and a few other tests) successfully. The commands to the tests were changed here, but the logic remains similar.

TODOS

• Decide how to make stor_swift, stor_s3, stor_dx as extras to stor, despite all of them being individual packages. Also, fix versioning so that it's impossible to have stor_swift==3.0.0 and stor_s3==3.0.1 on the same system

[jtratner]

as discussed:

Decide how to make stor_swift, stor_s3, stor_dx as extras to stor, despite all of them being individual packages. Also, fix versioning so that it's impossible to have stor_swift==3.0.0 and stor_s3==3.0.1 on the same system

Let's leave this for a follow-up PR.

For now, let's set this up so that stor requires stor_swift, stor_s3, and stor_dx (i.e., so pip install stor still works) and then can figure out version pinning.

[jtratner]

please add release notes and doc updates for how this changes things (i.e., about how each package is separated out, issues with versioning, the plugin infrastructure)

[anujkumar93]

Added the release notes and docs. Please have a look.

[jtratner]

after discussion with you - this is good to merge once changes made:

1. remove path_converted in favor of self
2. change name from find_cls_for_path to get_class_for_path (or class_for_path) for clarity

Then follow-up PR for additional doc changes