## Bug description

We've had a user create a funnel with Korean characters and 17 steps, which causes this issue:
![image](https://user-images.githubusercontent.com/1727427/120301818-8c212a00-c2cd-11eb-8b00-7ba242e4a9ab.png)

## Expected behavior

We should send requests to api/insight/funnel using POST instead of GET.

## How to reproduce

1.
2.
3.

## Environment

- [ ] PostHog Cloud
- [ ] self-hosted PostHog, version/commit: _please provide_

## Additional context



#### *Thank you* for your bug report – we love squashing them!

posthog/utils.py
"""
    Returns the symbolic name of the current active branch. Will return None in case of failure.
    Example: get_git_branch()
        => "master"
    """
    try:
        return (
            subprocess.check_output(["git", "rev-parse", "--symbolic-full-name", "--abbrev-ref", "HEAD"])
            .decode("utf-8")
            .strip()
        )
    except Exception:
        return None
def get_git_commit() -> Optional[str]:
    """
    Returns the short hash of the last commit.
    Example: get_git_commit()
        => "4ff54c8d"
    """
    try:
        return subprocess.check_output(["git", "rev-parse", "--short", "HEAD"]).decode("utf-8").strip()
    except Exception:
        return None
def render_template(template_name: str, request: HttpRequest, context: Dict = {}) -> HttpResponse: