Merge branch 'master' into dsuch-t-gh258-add-simple-scheduler
GH #258 - Working on the new scheduler.
GH #258 - Compute interval in seconds.
GH #258 - Working on job callbacks.
GH #258 - More of the internal scheduler's API.
GH #258 - More tests.
GH #258 - More tests.
GH #258 - Job tests.
GH #258 - Scheduler.create tests.
GH #258 - Tests for Job hash/eq methods.
GH #258 - Tests for Scheduler.run
GH #262 - Initial batch of updates.
Merge branch 'dsuch-t-gh262-flake8'
Merge branch 'master' into dsuch-t-gh258-add-simple-scheduler
GH #258 - Compute proper start_time for jobs starting in future.
GH #258 - Removing old helpers.
GH #258 - Compute start time for jobs with last run in past and next run in future.
GH #258 - Added handling of already expired jobs.
GH #258 - Jobs now invoke a callback on max repeats reached.
GH #258 - Make a job inactive on max repeats reached.