Common-blockchain compliance with latest cb-tester

This PR brings this module up to be compliant with `cb-tester: 0.1.x`.

Quite a lot of changes, definitely a major bump.  
For non-standard details that you have included, but are not yet merged up stream,  [I've made them double underscore prefixed](https://github.com/dcousens/cb-blockr/commit/26ce6e03b06f5326e6756483e222fef6fe9ca40f#diff-75db937239efccba78744416a68cd06fR54).