Upgrade to go 1.9.2

[samuelmanzer]

Hi folks, many thanks for creating this image, it's very useful.

I found that I wanted this feature mentioned in the go1.9 release notes:

Rows.Scan can now scan user-defined string types. Previously the package supported scanning into numeric types like type Int int64. It now also supports scanning into string types like type String string.

so I bumped the go version to 1.9.2 (latest stable version listed here). Our codebase seems to work fine on the new version, so might be worth making it available for others.

Unfortunately the PR won't bring the tag from make gitTag along with it, so y'all will have to handle that step.

Thanks for making this image!