build on python3
fix python3 and python2.7 runtime errors
Patched things for Python 3 support.
fixed range generator
added test case for range expression
Merge branch 'master' of https://github.com/yuzawa-san/croniter into spike_yuzawa-san

Conflicts:
	croniter/croniter.py
- Fixed bug: https://github.com/taichino/croniter/issues/20
- Added test case for the case above
- added timezone support
- added test case for timezone
added ipartola and yuzawa-san to contributors
added test for seconds repeating
fixed UnboundLocalError in proc_second

UnboundLocalError: local variable 'dst' referenced before assignment
removed useless for loop, now empty from previous bugfix
Update croniter.py

iterator protocol added
Merge remote-tracking branch 'gh1/master'
Merge remote-tracking branch 'gh2/master'
Merge remote-tracking branch 'gh3/patch-1'
style & pep8