add newline to sys.stderr.write

sys.stderr.write does not add automatically \n as print does.

Addressing:
Warning: remote.origin do not exist. Assuming --offline, for remote tag checking.Building package [osc-0.132.4-4]

And I checked all sys.stderr.write() occurence in code as well.
Merge pull request #90 from xsuchy/pull-req-newline

add newline to sys.stderr.write