Add URL data locators to launch sub-command (#920)

* initial commit of URL support for launch

* lint

* modify tests to use new data locator

* add locator unit tests

* fix typo in faq

* more lint

* update faq per PR review

server/app/driver/driver.py

@@ -46,7 +46,7 @@ class CXGDriver(metaclass=ABCMeta):
         return features
 
     @abstractmethod
-    def _load_data(self, data):
+    def _load_data(self, data_locator):
         pass
 
     @abstractmethod