Merge pull request #9 from maennel/master

Removing superfluous Crypto-dependency (already provided by pycrypto-package)
Worked on the support for elliptic curves
Merge branch 'master' of https://github.com/rohe/pyjwkest
Make sure the base64 encoded strings are base64url encoded.
Make sure the base64 encoded strings are base64url encoded.
Make sure text strings are text strings and not unicode strings.
Total refactoring, updated tests accordingly.
Total refactoring, updated tests accordingly. At last seems to work.
Made it so one can run the tests with 'setup.py test'.
Made it so one can run the tests with 'setup.py test'.
Added tox