Added optional `url` parameter to `github3.login` for a GitHubEnterprise
Set Makefile default goal to `tests` instead of `clean`

By virtue of being the first goal in the Makefile, `clean` is currently
the default. Personally I feel this is slightly aggressive (having
accidentally wiped out scratch files twice now due to bare `make`s) so
this sets `.DEFAULT_GOAL` to `tests`, which is non-destructive and
(based on no data other than my own usage) probably more desired.
Typo fix: "reqeust" -> "request"
Merge commit 'github/pr/87' into develop
Update CONTRIBUTING.rst
Update the login function on the API.

Also update the tests.
Merge branch 'pr/85' into develop
Add more links to the docs.

Closes #63
Last round of doc-changes before 0.6.0

It should be pushed out in the next few moments.
And so we begin again
Label equality
Bring coverage back up to 100%
Minor release for @alejandrogomez
And back to 0.7.0
support for tox
added tox to requirements.txt
correct logic for skipping tests
adding myself to Authors
Let's try this.
Merge branch 'pr/91' into develop