Basic app structure
Initial eunit tests
Add lhttpc to deps
Refactor code

Other changes:
* Add direct card processing and direct money transfer
* Extend the eunit test fixture
* Start crypto and lhttpc when/before application starts
Update README
Add OPR operations
Update test fixture
Add .travis.yml
Test reformatting of taxes
Add `create invoice` API call

Also includes minor code refactoring
Rename LICENSE.txt to LICENSE