Allow overriding Eve settings from env in test

Environment variables for Eve settings are now used in unit tests.

tests/common_test_settings.py

@@ -1,3 +1,13 @@
 from settings import *
 
 from eve.tests.test_settings import MONGO_DBNAME
+
+
+def override_eve():
+    from eve.tests import test_settings
+    from eve import tests
+
+    test_settings.MONGO_HOST = MONGO_HOST
+    test_settings.MONGO_PORT = MONGO_PORT
+    tests.MONGO_HOST = MONGO_HOST
+    tests.MONGO_PORT = MONGO_PORT