Import "C" and Go standard generated comments

Fixes #11 (bringing generated comment line into compliance with Go standard in order to avoid linting)

Fixes #12 (ignoring 'import "C"' to avoid problems)

Remove before gen

imports-gen now removes the imports_${GOOS}.go file before scanning for package dependencies in order to avoid its imports being found.

v1.1.0: Updating import-gen to be properly GOOS aware.

This represents a bit of a shift in imports-gen in that instead of generating an imports.go file, it generates an imports_{{GOOS}}.go file.

Since this represents a minor shift in the API of imports-gen, this is a minor release bump.

v1.0.1: Merge pull request #7 from edwarnicke/go1.14

Support .TestImports

Initial release

Merge pull request #5 from edwarnicke/upgrade

Update exechelper