Rename Tools/Scripts/webkitpy/bindings/main.py to bindings_tests.py

Some scripts in Source/bindings/scripts aren't executed while building
chromium. These scripts should be placed in another place and
Tools/Scripts/webkitpy/bindings is a good candidate to put tool-ish scripts.
This CL renames main.py in the directory so that we can put other scripts
in the directory.

Also, I did some clean-ups to pass check-webkit-style.

BUG=617899

Review-Url: https://codereview.chromium.org/2166223002
Cr-Commit-Position: refs/heads/master@{#406796}
3 files changed