* Add assertions for call args for some bitcoin client mocks
* Simplify bitcoin core client
* Add assertions on call args for getblockcount
* Add test for make_request method of bitcoin core client
* Use make_request method for bitcoin connection error tests
* Remove old comments
* Use call arg assertions for all methods of bitcoin core client
* Add tests for bitcoin client get count method
* Rename bitcoin exceptions
* Got test working for bitcoin http error
* Added tests for get block count and get block hash
* Added tests for all bitcoin client methods
* Added tests for invalid results
* Remove check for empty result which is not needed
* Add test for all bitcoin request errors
* Rename bitcoin connection error exception
* Remove print statments from bitcoin client
* Got 100% coverage for bitcoin client
* Add todos to assert mocks called with correct args
* Rename bitcoin core client class and module