Added `group_id` and `until_group()` to flow (#19)

* Added `group_id` and `until_group()` to flow

* Moved `ensure_hash(group_id)` outside the loop

New flow.until_flows api (#17)

Co-authored-by: Mikhail Gudkov <mikhail.gudkov@playrix.com>

Nice traceback on error in flow module (#16)

Added flow collection factory and factory load

Fixes #8

Run flows immediately when started

Fixes #14

Changed timer interval to get one update per frame and accurate timing

Fixes #12

Update json.lua

Resume immediately when messages or input is received

Fixes #7

Update sequence.lua

Added sequence.wait_until_true() and wait_until_false()