adding test cases and reworking test env

tests/test_Roles.py

@@ -0,0 +1,43 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+from __future__ import with_statement
+from __future__ import unicode_literals
+
+import pytest
+import sys
+from ldapcherry.roles import Roles
+from ldapcherry.pyyamlwrapper import DumplicatedKey, RelationError
+
+
+class TestError(object):
+
+    def testNominal(self):
+        inv = Roles('./tests/cfg/roles.yml')
+        print inv.roles
+        return True
+
+    def testMissingDisplayName(self):
+        try:
+            inv = Roles('./cfg/roles_missing_diplay_name.yml')
+        except MissingKey:
+            return
+        else:
+            raise AssertionError("expected an exception")
+
+    def testRoleKeyDuplication(self):
+        try:
+            inv = Roles('./tests/cfg/roles_key_dup.yml')
+        except DumplicateRoleKey:
+            return
+        else:
+            raise AssertionError("expected an exception")
+
+    def testRoleContentDuplication(self):
+        try:
+            inv = Roles('./tests/cfg/roles_content_dump.yml')
+        except DumplicateRoleContent:
+            return
+        else:
+            raise AssertionError("expected an exception")
+