move base test classes to oftest.base_tests

This lets them be shared between separate directories of tests.
diff --git a/tests/caps.py b/tests/caps.py
index ae218f0..fe90310 100644
--- a/tests/caps.py
+++ b/tests/caps.py
@@ -14,7 +14,7 @@
 import oftest.dataplane as dataplane
 import oftest.action as action
 import oftest.parse as parse
-import basic
+import oftest.base_tests as base_tests
 
 from oftest.testutils import *
 
@@ -88,7 +88,7 @@
     logging.error("RESULT: " + str(active_flows) + " flows reported")
 
 
-class FillTableExact(basic.SimpleProtocol):
+class FillTableExact(base_tests.SimpleProtocol):
     """
     Fill the flow table with exact matches; can take a while
 
@@ -112,7 +112,7 @@
         logging.info("Running " + str(self))
         flow_caps_common(self)
 
-class FillTableWC(basic.SimpleProtocol):
+class FillTableWC(base_tests.SimpleProtocol):
     """
     Fill the flow table with wildcard matches