## 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
from posthog.models import User
    try:
        User.objects.count()
        return True
    except DatabaseError:
        return False
def is_redis_alive() -> bool:
    try:
        get_redis_info()
        return True
    except BaseException:
        return False
def is_celery_alive() -> bool:
    try:
        return get_celery_heartbeat() != "offline"
    except BaseException:
        return False
def is_plugin_server_alive() -> bool:
    try:
        ping = get_client().get("@posthog-plugin-server/ping")
        return bool(ping and parser.isoparse(ping) > timezone.now() - relativedelta(seconds=30))
    except BaseException:
        return False
def get_plugin_server_version() -> Optional[str]:
    cache_key_value = get_client().get("@posthog-plugin-server/version")
    if cache_key_value:
        return cache_key_value.decode("utf-8")
    return None
def get_plugin_server_job_queues() -> Optional[List[str]]: