updated code to work with Python 3.6

[Mestalbet]

The file had the wrong name and wouldn't run due to "raw_input" (now called input) and "unicode" (now called str) functions. Also, expected to receive u'' which is no longer necessary in Python 3.

[fabriceb]

Thanks @Mestalbet for this! I am happy to merge, I am just surprised that the diff is 100% of the file content, why is that?

[Mestalbet]

Actually, I am not sure why it's 100% diff. That's super weird. It probably has to do with a combination of (a) me not remembering anymore and (b) me being a bit of an idiot somehow. :)

[Mestalbet]

Ah - it's because the comments give the usage as "python gcalcron2.py" but the script is called "gcaclron.py" so I changed the file name to gcalcron2.py to conform to the usage instructions. Since there is no "gcalcron2.py" in your repo it's a 100% diff.