Bug fixes and improvements

[tom-price]

OK, I'm re-implementing whats in PR #24 in two parts and this is the first step with the args+kwargs implementation built atop it to addresses issue #1. Here's an overview of the changes:

• Changed
• Version bumps on requirements for Django-RQ and rq-scheduler to account for RQ's version 1.0 and changes in Redis v3.
• Tests now run using fakeredis and don't pollute your Redis instance.
• Overall the tests have been restructured to take advantage of all of Factory's features. All past tests are still present and there are new ones bringing test coverage of models.py to 100%
• Improvements on PR #29 have been made adding seconds as an available interval unit following my comments. Driven by Issue #28
• Added prevention of the ability to set a repeatable job with a result_ttl shorter than the interval time. See the relevant important note here https://github.com/rq/rq-scheduler
• Moved the enable disable checkboxes to a bulk enable / disable action for a simpler UX (not having both a "Go" and "Save" button. Change permissions are respected.
• Added the ability to immediately run jobs as a bulk action based upon an improvement in UKTV's fork.