Add Drone CI

[sdarwin]

Add Drone CI integration.
All these files were generated by the new (still in-progress) CPPAlliance/droneconverter.

cd static_string
./droneconverter

[codecov]

Codecov Report

Merging #14 (6db65c3) into develop (c59150c) will not change coverage.
The diff coverage is n/a.

❗ Current head 6db65c3 differs from pull request most recent head 10045d4. Consider uploading reports for the commit 10045d4 to get more accurate results

@@            Coverage Diff            @@
##           develop       #14   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files            1         1           
  Lines          862       862           
=========================================
  Hits           862       862           

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