AppVeyor Support

[RichardSlater]

Add EVEMon to AppVeyor with YAML Configuration.

Tasks still to complete after merging pull request:

1. Visit AppVeyor and create an EVEMonDevTeam account.
2. Authenticate with GitHub and add the repository.
3. Bump the build version to 4.
4. Start a new build.

We might need to talk about using SymVer and numbering our builds 3.0.4-alpha2.

[JimiC]

@RichardSlater EVEMon already follows SymVer and I made it ready to support any of its formats.

[RichardSlater]

@JimiC I was actually thinking more specifically what we number our builds generated by a CI/CD pipeline - i.e. do we call it 3.0.4-alpha{buildNum} or 3.0.4-beta{buildNum} etc. Great that EVEMon works with SemVer already though.

[JimiC]

@RichardSlater I don't know if it's worth it when you don't have a mechanism that distributes the snapshots like we used to have with BattleClinic.