List of contributors (#340)

* Updated copyright years. Same copyright holders in code and LICENSE

* Contributor list. Order is from contributors gh page

CONTRIBUTORS.md

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+# CPM.cmake Contributors
+
+For detailed breakdown of individual contributions see the [Contributors page on GitHub](https://github.com/cpm-cmake/CPM.cmake/graphs/contributors)
+
+* [Lars Melchior](https://github.com/TheLartians)
+* [Borislav Stanimirov](https://github.com/iboB)
+* [Paul T](https://github.com/DeveloperPaul123)
+* [Leonardo Lima](https://github.com/leozz37)
+* [pgorgon-hem](https://github.com/pgorgon-hem)
+* [Xavier Muller](https://github.com/xmuller)
+* NVIDIA CORPORATION via [Robert Maynard](https://github.com/robertmaynard)
+* [Kingsley Chen](https://github.com/kingsamchen)
+* [alexandreSalconiDenis](https://github.com/alexandreSalconiDenis)
+* [DNKpp](https://github.com/DNKpp)
+* [Olivier Le Doeuff](https://github.com/OlivierLDff)
+* [Stuart Dootson](https://github.com/studoot)
+* [Tobias Hellmann](https://github.com/Tobi823)
+* [Giuseppe Cesarano](https://github.com/GiuseppeCesarano)
+* [Pavel Sokolov](https://github.com/hacker-cb)
+* [Claus Klein](https://github.com/ClausKlein)
+* [Clare Macrae](https://github.com/claremacrae)
+* [Kai Germaschewski](https://github.com/germasch)
+* [Andrea Barbadoro](https://github.com/andijcr)
+* [MixusMinimax](https://github.com/MixusMinimax)
+* [Dan Raviv](https://github.com/danra)
+* [Prabir Shrestha](https://github.com/prabirshrestha)
+* [Paul Taylor](https://github.com/trxcllnt)
+* [Ryan Mast](https://github.com/nightlark)
+* [Vinpasso](https://github.com/Vinpasso)
+* [Yotam Gingold](https://github.com/yig)
+* [jecassis](https://github.com/jecassis)
+* [Johel Ernesto Guerrero Peña](https://github.com/JohelEGP)