### navigate_to_first_post_after_read setting for categories
When enabled on categories logged on users will return to OP after
reading the entire category. (useful for documentation categories)
### num_auto_bump_daily
Set a number of topics that will automatically bump daily on a category.
- Every 15 minutes we will check if any category has this setting
- Categories with the setting are shuffled
- We exclude pinned, closed, category description and archived topics
- Maximum of 1 topic for the list of categories is bumped till limit reached per category
- We always try to bump oldest first
- Limit is elastic using a RateLimiter that ensures that we only bump N per day
Also some minor organisation on category settings
Froze strings on category.rb
This updates tests to use latest rails 5 practice
and updates ALL dependencies that could be updated
Performance testing shows that performance has not regressed
if anything it is marginally faster now.
