Trying an alternative way to add route handlers.
Fixes merge conflict.
Merge branch 'feature/add_mysql_backend' of github.com:jcarley/gorunner into feature/add_mysql_backend

* 'feature/add_mysql_backend' of github.com:jcarley/gorunner:
  Implements tests for add task handler.
  Refactors tests to use NewAppContext test helper method.
  Converts ListTasks to AppContext route.  Implements tests for ListTasks.
  Removes old code.  Updated ListJobs test to new AppContext test helper function.
  Removes the test for Job#AppendTask.  Not needed anymore.
  Implements remove trigger from Job.
  Handles truncating tables for each test example.
  Migration to add foreign keys to job_triggers table.
  Migration to add foreign keys to job_tasks table.