Adding ES256/384/512 support
Rename RSA assets in tests
First pass at ECDSA tests
Increasing expiration length to get through all tests.
Update README with ECDSA-relevant changes.
Some README clarifications.
Fixing signature R and S value encoding, add tests for it
Adding ecdsa library to test requirements.
Merge pull request #1 from progrium/master

Merge in base master at a99f40
Merging in from latest master; resolving merge conflicts
Merge pull request #40 from sullivanmatt/master

Support for Elliptic Curve signatures (ES256 / ES384 / ES512)