normalize package name for PyPI wheel compliance

Author: vgrem

setup.py

@@ -8,7 +8,7 @@
     long_description = fh.read()
 
 setup(
-    name="Office365-REST-Python-Client",
+    name="office365-rest-python-client",
     version="2.6.2",
     author="Vadim Gremyachev",
     author_email="[email protected]",