Don't use the KEYS command in redis.

This command is dangerous and often disabled.
Don't crash when using KEYS in sidetiq/web.
Merge branch 'dont-use-redis-keys' of https://github.com/Connorhd/sidetiq into Connorhd-dont-use-redis-keys

Conflicts:
	lib/sidetiq/schedulable.rb
Merge branch 'Connorhd-dont-use-redis-keys'