edit.py now checks validity of jobs, prompts user to correct invalid crontabs, and opens the crontab via preferred text editor, if available. Otherwise it prompts user to set a preferred text editor and exits.
Replaced python-crontab validity check with a version using croniter. Adjusted style. Now continuously prompts user to edit their invalid crontab.
Minor style error (one trailing whitespace character).
Small stylistic changes. Store boolean for amount of params, and no newline after prompt.
Removed main function call, made the prompt response case-insensitive, and added ValueError to the except for validating jobs.
Now displays the invalid crontab the user attempted to input, if they decide to edit it.
Merge branch 'master' of https://github.com/BigFav/MegaCron into fnc4
Removed bad elif statement.
Removed useless "valid_interval" variable
Merge pull request #35 from BigFav/fnc4

edit.py Update