Add --raw option to ansible-test shell command.

It is currently supported only with the `--remote` option.

This makes it easier to troubleshoot new instances which are not
yet supported by the setup scripts used by ansible-test.

test/runner/lib/config.py

@@ -134,6 +134,11 @@ class ShellConfig(EnvironmentConfig):
         """
         super(ShellConfig, self).__init__(args, 'shell')
 
+        self.raw = args.raw  # type: bool
+
+        if self.raw:
+            self.httptester = False
+
 
 class SanityConfig(TestConfig):
     """Configuration for the sanity command."""