docs in Txbuilder
up to version 0.1.18

Critical bug fix - generating k was insecure:

https://github.com/bitpay/bitcore/pull/309
[#312] remove test from ignore in bower.json
Merge pull request #313 from JahPowerBit/master

[#312] remove test from ignore in bower.json
add docs to Address class
Merge pull request #314 from matiu/feature/docs02

Feature/docs02