create rc file if does not exist

Installed with ```sudo pip install percol```
Getting below exception. 
Issue is rc file wan't created. This is patch for this issue.
```
Traceback (most recent call last):
  File "/usr/local/bin/percol", line 32, in <module>
    main()
  File "/usr/local/lib/python2.7/dist-packages/percol/cli.py", line 228, in main
    load_rc(percol, options.rcfile)
  File "/usr/local/lib/python2.7/dist-packages/percol/cli.py", line 65, in load_rc
    raise LoadRunCommandFileError(e)
percol.cli.LoadRunCommandFileError: Error in rc.py: [Errno 2] No such file or directory: '/usr/local/lib/python2.7/dist-packages/percol/rc.py'
```