See available versions of Go at https://www.appveyor.com/docs/installed-software/#go
Use go 1.7.1 for testing
Seems the default has switched to 1.7, but we still use go 1.6.
Influxdb uses gdm for the dependency management. For gdm to work on Windows, it needs go 1.6. Influx still uses go 1.4.3. So go 1.6 will be sed for the pre-build stages, and go 1.4.3 to run the tests. This arrangements is working in AppVeyor now.