Adds a test framework that allows tests to inject fake/mock
dependencies into the vulnreport commands and record the expected
output of commands.
Some subcommand tests are left as TODOs, as they require additional
fake/mock dependencies that haven't been implemented yet.
Change-Id: I25f6085f2297e5b9d916f0927c1111ac2b49bef8
Reviewed-on: https://go-review.googlesource.com/c/vulndb/+/590038
Reviewed-by: Damien Neil <dneil@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Tatiana Bradley