CLI script to gather environment info (#2699)

* add "info" command to CLI

As a convenience, add the info directive to CLI. Running `python transformers-cli info` will return a string containing the transformers version, platform, python version, PT/TF version and GPU support

* Swap f-strings for .format

Still supporting 3.5 so can't use f-strings (sad face)

* Add reference in issue to CLI

* Add the expected fields to issue template

This way, people can still add the information manually if they want. (Though I fear they'll just ignore it.)

* Remove heading from output

* black-ify

* order of imports

Should ensure isort test passes

* use is_X_available over import..pass

* style

* fix copy-paste bug

* Rename command info -> env

Also adds the command to CONTRIBUTING.md in "Did you find a bug" section

transformers-cli

@@ -1,11 +1,12 @@
 #!/usr/bin/env python
 from argparse import ArgumentParser
 
-from transformers.commands.download import DownloadCommand
-from transformers.commands.run import RunCommand
-from transformers.commands.user import UserCommands
 from transformers.commands.convert import ConvertCommand
+from transformers.commands.download import DownloadCommand
+from transformers.commands.env import EnvironmentCommand
+from transformers.commands.run import RunCommand
 from transformers.commands.serving import ServeCommand
+from transformers.commands.user import UserCommands
 
 if __name__ == '__main__':
     parser = ArgumentParser('Transformers CLI tool', usage='transformers-cli <command> [<args>]')
@@ -14,6 +15,7 @@ if __name__ == '__main__':
     # Register commands
     ConvertCommand.register_subcommand(commands_parser)
     DownloadCommand.register_subcommand(commands_parser)
+    EnvironmentCommand.register_subcommand(commands_parser)
     RunCommand.register_subcommand(commands_parser)
     ServeCommand.register_subcommand(commands_parser)
     UserCommands.register_subcommand(commands_parser)