Set executable bit when copying example code

[awdeorio]

Set executable bit when copying example code so that example runs out-of-the-box.

Closes #85

[codecov]

Codecov Report

❌ Patch coverage is 0% with 6 lines in your changes missing coverage. Please review.
✅ Project coverage is 77.45%. Comparing base (2f41481) to head (0e51b47).
⚠️ Report is 2 commits behind head on develop.

Files with missing lines	Patch %	Lines
madoop/__main__.py	0.00%	6 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop      #87      +/-   ##
===========================================
- Coverage    79.18%   77.45%   -1.73%     
===========================================
  Files            4        4              
  Lines          269      275       +6     
===========================================
  Hits           213      213              
- Misses          56       62       +6     

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[garv8]

LGTM