add first pytest unit tests

[tomsilver]

also make bathing and dressing environments easier to create

[YoruCathy]

I think the current version is good to merge but added some cmments regarding making the path more configurable and adding cache for the conda env to make the workflow faster.

[YoruCathy]

For these path, should we consider using some more configurable formats?

Something like:

from pathlib import Path
from pyrcareworld.envs.base_env import RCareWorld

class DressingEnv(RCareWorld):
    """Dressing environment for the PhyRC competition."""

    def __init__(self, template_path=None, executable_path=None, *args, **kwargs):
        # Allow paths to be passed as arguments or use defaults
        template_path = Path(template_path or Path(__file__).parents[3] / "template")
        executable_path = Path(executable_path or template_path / "Dressing" / "DressingPlayer.x86_64")
        
        super().__init__(executable_file=str(executable_path), *args, **kwargs)

[tomsilver]

Thanks for the feedback! I made executable_path configurable, but I figure that we probably won't need to configure template_path separately from that.

[YoruCathy]

Should we cache the conda env?

[tomsilver]

This is a good idea, but I couldn't figure out exactly the right way to do this after looking at it for a bit, so I'll save this for a future PR!