Fixed typo and added some documentation.

.travis.yml

@@ -18,7 +18,7 @@ install:
 - pip install -r monkey/infection_monkey/requirements_linux.txt  # for unit tests
 
 before_script:
-# Set the server config to `testing`, for the UTs to use mongomaock and pass.
+# Set the server config to `testing`. This is required for for the UTs to pass.
 - python monkey/monkey_island/cc/set_server_config.py testing
 
 script:

monkey/monkey_island/cc/environment/testing.py

@@ -2,6 +2,10 @@ from monkey_island.cc.environment import Environment
 
 
 class TestingEnvironment(Environment):
+    """
+    Use this environment for running Unit Tests.
+    This will cause all mongo connections to happen via `mongomock` instead of using an actual mongodb instance.    
+    """
     def __init__(self):
         super(TestingEnvironment, self).__init__()
         self.testing = True

monkey/monkey_island/cc/models/__init__.py

@@ -6,7 +6,7 @@ from monkey_island.cc.environment.environment import env
 #   If testing, use mongomock which only emulates mongo. for more information, see
 #   http://docs.mongoengine.org/guide/mongomock.html .
 #   Otherwise, use an actual mongod instance with connection parameters supplied by env.
-if env.testing:
+if env.testing:  # See monkey_island.cc.environment.testing
     connect('mongoenginetest', host='mongomock://localhost')
 else:
     connect(db=env.mongo_db_name, host=env.mongo_db_host, port=env.mongo_db_port)