Building gotestsum started to fail after the repository removed some
dependencies on master.
What happens is that first, we `go get` the package (with go modules disabled);
GO111MODULE=off go get -d gotest.tools/gotestsum
Which gets the latest version from master, and fetches the dependencies used
on master. Then we checkout the version we want to install (for example `v0.3.5`)
and run go build.
However, `v0.3.5` depends on logrus, and given that we ran `go get` for `master`,
that dependency was not fetched, and build fails.
This patch modifies the installer to use go modules (alternatively we could
probably run `go get .` after checking out the `v0.3.5` version),
We need to modify all installers, as it looks like this is a standard pattern
we use, but other dependencies were not failing (yet), so this patch only
addresses the immediate failure.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>