Update setup.py for azure-keyvault

comma is missing in install_requires, so fixing it.

Author: anubhav-s

azure-keyvault/setup.py

@@ -79,7 +79,7 @@
     packages=find_packages(),
     install_requires=[
         'msrestazure>=0.4.15',
-        'msrest>=0.4.17'
+        'msrest>=0.4.17',
         'azure-common~=1.1.5',
     ],
     cmdclass=cmdclass