Have skeleton pypi get metadata from package itself where possible

It still falls back to the metadata from PyPI. This is the first step to
allowing skeleton pypi to be run on a url without the PyPI xmlrpc interface.
Remove extra space before license text in skeleton pypi
Only dump necessary info in distutils patch

The full setup() kwargs may contain things that can't be yaml serialized, like
objects defined in setup.py.
Multiple packages with --no-download warning is no longer relevant
pypi: Move extraction of package metadata into its own function
Allow to pass a url to conda skeleton pypi

Fixes #150.
The home page field in setup() is called 'url'
The summary in setup() is called "description"
Fix key name
Use parse_url even with pypi urls in skeleton pypi

This fixes issues where the filetype of a url with an md5 at the end won't be
recognized.

Fixes conda/conda#933.
Move the test recipes into tests
Add a skeleton test
skeleton pypi: extract md5 from url fragment
Add test for skeleton pypi url
Run the skeleton tests in Travis
mktemp requires some X's in Linux
Fix recipe tests from directory move
Merge pull request #216 from asmeurer/pypi-url

Allow urls in skeleton pypi (without accessing pypi)