Add golang github actions

[jooola]

This will add some CI testing linting and building.

A test needs to be fixed. Please either edit my PR or fix it in master I'll rebase upon the fix.

[jooola]

Please see https://github.com/jooola/zabbixctl/runs/323253297

[kovetskiy]

I've fixed the issue, could you please rebase your fork and check that action?

[jooola]

Done, this is now a basic CI. I'll submit another PR to setup release process.

Also I might come up with a bigger PR to restructure the project.

[jooola]

See https://github.com/jooola/zabbixctl/runs/323476691

[kovetskiy]

Thanks!