Update to version 02 of the draft specification

[sbellem]

draft is at https://tools.ietf.org/html/draft-thomas-crypto-conditions-02

• [x] part of this work should incorporate the test vectors documented at https://github.com/rfcs/crypto-conditions#test-vectors

Some details to double check for:

• [ ] URI normalization: see issues https://github.com/rfcs/crypto-conditions/pull/8 and https://github.com/rfcs/crypto-conditions/issues/12
• [x] add condition validation to tests
• [x] document support for subtypes (which ones) and behaviour of the implementation with respect to unsupported types (types above id 4 are ignored)

Things left to be done

• [ ] Test signature operation (see https://github.com/rfcs/crypto-conditions/issues/15)

[sappenin]

FYI - rfcs/crypto-conditions#8 and rfcs/crypto-conditions#12 are resolved via draft-03 of the cryptoconditions specification.

[sbellem]

FYI - rfcs/crypto-conditions#8 and rfcs/crypto-conditions#12 are resolved via draft-03 of the cryptoconditions specification.

Thanks @sappenin!