rename to match others

Signed-off-by: Steven Armstrong <steven@icarus.ethz.ch>

lib/cdist/test/test_exec.py

@@ -29,7 +29,7 @@ import unittest
 import cdist.exec
 
 
-class Exec(unittest.TestCase):
+class ExecTestCase(unittest.TestCase):
     def setUp(self):
         """Create shell code and co."""