removes command caching on retrieve from netcli

The caching of commands in CommandRunner is providing no useful feature
and causing problems.  This removes the code and simply returns the
requested command results.

lib/ansible/module_utils/netcli.py

@@ -127,7 +127,6 @@ class CommandRunner(object):
 
         self.match = 'all'
 
-        self._cache = dict()
         self._default_output = module.connection.default_output
 
 
@@ -140,15 +139,9 @@ class CommandRunner(object):
         self.commands.append(cmd)
 
     def get_command(self, command, output=None):
-        output = output or self._default_output
-        try:
-            cmdobj = self._cache[(command, output)]
-            return cmdobj.response
-        except KeyError:
-            for cmd in self.commands:
-                if cmd.command == command and cmd.output == output:
-                    self._cache[(command, output)] = cmd
-                    return cmd.response
+        for cmd in self.commands:
+            if cmd.command == command:
+                return cmd.response
         raise ValueError("command '%s' not found" % command)
 
     def get_responses(self):