`from_input` method should load taskrc_location and data_location

Hi, I'm writing some hooks and I noticed that the `from_input` method loads a TaskWarrior backend with the following configuration

```python
backend = backends.TaskWarrior(data_location=hook_parent_dir)
```

Therefore it loads the data from the hook parent directory but the configuration from `~/.taskrc`.

Now with the hooks V2 it would be as easy as to load those two values from `sys.argv`.

I'm willing to do a Pull Request if you are interested.

Please let me know