Changelog for clifford-0.1.0.7

--change-log-- 0.1.0.7 Adding basic linear operators; made multivector a field 0.1.0.6 Memoising the blade index comparision function for a 20% speed increase 0.1.0.5 Adding hspec tests, fixed blade comparison to order blades in terms of grade first

0.1.0.4 Made multivectors have a (p,q) metric signature at the type level