Add multiple executors

Refactoring / clean up
Adding executors instead of framework messages
update code per review
fix order of imports
Test correct functionality in config
Consistent ordering for shell commands
Disable hostname check

DNS may not be configured in which case we want to use IP not hostname
Update Scheduler / Executor

- Update per review comments
- Use IP address instead of hostname
- Create directory needed for hdfs
Add comment for configuration
Update executors and conf per review
Clean up / updates per review

- Return task running message after task has been launched
- Remove unnecessary code from scheduler
- Add TODO’s
update log statement
Merge pull request #22 from mesosphere/refactor-classes

Add multiple executors