Fix superqueuer exception when no jobs are queued

Bug Fixes:

• Fix superqueuer exception when no jobs are queued

Other Changes:

• Use hodor/ravens for \Hodor\MessageQueue classes
• Add PHP 7.1 to CI
• Explicitly name sequence and primary key names
• Add Docker development environment
• Move scheduled jobs to a separate table

Refactor and testing initiative

Breaking Changes:

• Upgraded Hodor's dependency on lightster/yo-pdo to v0.1.3+ from v0.0.2+
• Deprecated \Hodor\JobQueueFacade and will remove in 0.3.0

Bug Fixes:

• Stop attempting to mark job as failed if it has already been marked as successful
  (#213)

Other Changes:

• Refactored internals on a massive scale
• Increased testing coverage
• Improved PHPdoc

v0.1.0

Merge pull request #125 from lightster/issue_124_fix_db_migrate_on_fr…

Add support for batch publishing messages

v0.0.6

Merge pull request #100 from lightster/issue_93_test_multiple_superqu…

Commit every job's DB transaction before pushing to Rabbit

• Commit every job's DB transaction before pushing to Rabbit

Prevent competing Superqueuers

• Fix the issue in which the superqueuer was sleeping without exit
  when it could not acquire the superqueue lock
• Limit job_params nesting to prevent encodingissues

Lots of enhancements

• Add superqueuer
  • Add job ranking
  • Add future job scheduling
• Add supervisord config generator
• Add job option validation
• Prevent blank jobs caused by extreme nesting of job_params
• Replace DBAL internals with PDO-based library
  • Using pg_* methods was becoming overly complicated
• Expand test suite

Remove unused dependencies; add connection option

• Remove unused dependencies
• Add option to connect to RabbitMQ using sockets rather than streams

Add buffer queue

v0.0.1

refactor(cli): reduce argument processing duplication

Initial release: worker queue only

The bare minimum seems to be working: job pushing and job running.