Adds implementation of get_distribution_and_version for Windows

* Adds the get_distribution_and_version method to the windows_client
* Added get_distribution_and_version to the base remote client to
  enforce its implementation in child clients

Change-Id: I9a91d04018709dfd92325a64af85d2c37fc4d99b

cloudcafe/compute/common/clients/remote_instance/base_client.py

@@ -57,3 +57,7 @@ class RemoteInstanceClient(BaseClient):
     def can_authenticate(self):
         """Verifies a remote connection can be made to the server."""
         raise NotImplementedError
+
+    def get_distribution_and_version(self):
+        """Gets the distribution and version of a server."""
+        raise NotImplementedError

cloudcafe/compute/common/clients/remote_instance/windows/windows_client.py

@@ -485,11 +485,26 @@ class WindowsClient(RemoteInstanceClient):
         output = self.client.execute_command(command)
         return output.std_out[0]
 
+    def get_distribution_and_version(self):
+        """
+        Gets the distribution and version of a server
+        @return: Full name of the distribution
+        @rtype: str
+        """
+        output = self.client.execute_command(
+            'powershell gwmi win32_operatingsystem |% caption')
+        if output.std_out:
+            return output.std_out
+        else:
+            return ''
+
     def filesystem_sync(self):
         # This works as a non-powershell command, but it may not
         # be installed on all versions of windows.
         self.client.execute_command('sync')
 
+    # gwmi
+
     @staticmethod
     def _convert_powershell_list_to_dict(response):
         data = {}