Automated release creation through GitHub workflow

Remove AppVeyor builds, since we're no longer using it for releases.

(OPTIONAL) Added AppVeyor automated builds

Version 2017.3.23

Version 2017.2.15

Version 2016.2.22

Version 2016.2.15

Version 2015.3.14.

Version 2015.3.13.

Set release version 2015.3.5

Version 2014.2.15