Update the kmip package to allow importing enums globally

This change updates the root-level kmip package, allowing users
to now import enums directly from the kmip package:

from kmip import enums

Enumerations are used throughout the codebase and user applications
and this will simplify usage and help obfuscate internal package
details that may change in the future.

kmip/__init__.py

@@ -16,6 +16,8 @@
 import os
 import re
 
+from kmip.core import enums
+
 # Dynamically set __version__
 version_path = os.path.join(os.path.dirname(
     os.path.realpath(__file__)), 'version.py')
@@ -24,4 +26,9 @@ with open(version_path, 'r') as version_file:
     __version__ = mo.group(1)
 
 
-__all__ = ['core', 'demos', 'services']
+__all__ = [
+    'core',
+    'demos',
+    'enums',
+    'services'
+]