fixed a bug in displaying Key Expiration Time
new testdata; new public keys; regenerated keyrings
tests updated to use new testdata or new testdata locations where necessary
initial testing of signatures
added support for Policy URL subpackets
added support for Policy URL subpackets
added a new exception class: WontImplementError, to raise in cases where things will not be implemented (such as encrypting key material with IDEA)
added a method to PGPSignature to handle computation of signature hashes
added new file `signature.py` which contains (so far) a single class: SignatureVerification, which is returned from PGPKeyring.verify() and is comparable as a boolean.
pyca/cryptography's current release (0.3) does not support DSA yet, so I've marked the Ubuntu signature verification as "expected to fail" until that point.
RSA Signature verification, woohoo! It's passing the unit tests so far! :)
changed member function PGPSignature.hash() to PGPSignature.hashdata(), as our signature verification provider wants to do the hashing part itself.
slightly more output - this may not stay as it is.
changed the travis badge to svg, and added some additional information
Merge branch 'feature/verify_rsa_signatures' into develop