switch to using Popen to execute cmd

[chrisvaughn]

• gives control over how to handle stdout
• allows for logging output in realtime for long running crons

[chrisvaughn]

for testing I did the following:

basic test case

>> ./crony-runner.py echo "hello"
2017-12-03T08:34:47 INFO: No config file found.
2017-12-03T08:34:47 INFO: hello

error case

>> ./crony-runner.py cat /filethatdoesntexist
2017-12-03T08:35:43 INFO: No config file found.
2017-12-03T08:35:43 INFO: cat: /filethatdoesntexist: No such file or directory
2017-12-03T08:35:43 ERROR: Error running command! Exit status: 1, cat: /filethatdoesntexist: No such file or directory
>> echo $?
1

case for output while command is running

1. create a test file runloop.sh

   for number in {1..10}; do echo "$number "; sleep 1; done

2. execute

   
   >> ./crony-runner.py bash runloop.sh
   2017-12-03T08:38:23 INFO: No config file found.
   2017-12-03T08:38:23 INFO: 1
   2017-12-03T08:38:24 INFO: 2
   2017-12-03T08:38:25 INFO: 3
   2017-12-03T08:38:26 INFO: 4
   2017-12-03T08:38:27 INFO: 5
   2017-12-03T08:38:28 INFO: 6
   2017-12-03T08:38:29 INFO: 7
   2017-12-03T08:38:30 INFO: 8
   2017-12-03T08:38:31 INFO: 9
   2017-12-03T08:38:32 INFO: 10
   >> echo $?
   0

[chrisvaughn]

Fixes #9

[bbelyeu]

👀 💯 👍

[bbelyeu]

next time if you add "Fixes #9" in the commit message when it's merged I believe it auto closes the open issue.

[bbelyeu]

https://help.github.com/articles/closing-issues-using-keywords/#closing-an-issue-in-the-same-repository