Raise Error when release not exist in uninstall_release

[joaquinCaceres]

Hi!

Thanks for the implementation of this repo. It is very useful!

I think that in the uninstall_release function it would be interesting to throw an error when the release is not found. That way we let the user, who calls the function, decide for himself what to do.

    async def uninstall_release(
        self,
        release_name: str,
        *,
        dry_run: bool = False,
        keep_history: bool = False,
        namespace: t.Optional[str] = None,
        no_hooks: bool = False,
        timeout: t.Union[int, str, None] = None,
        wait: bool = False
    ):
        """
        Uninstall the named release.
        """
        try:
            await self._command.uninstall(
                release_name,
                dry_run = dry_run,
                keep_history = keep_history,
                namespace = namespace,
                no_hooks = no_hooks,
                timeout = timeout,
                wait = wait
            )
        except ReleaseNotFoundError:
            # If the release does not exist, it is deleted :-)
            pass