Add e2e tests for slsa-github-generator v1.2.2 (#355)

* Add e2e tests for slsa-github-generator v1.2.2

* Fix testdata

Signed-off-by: Ian Lewis <ianmlewis@gmail.com>

.gitignore

@@ -1 +1,2 @@
 .idea
+vendor

cli/slsa-verifier/main_test.go

@@ -554,7 +554,7 @@ func Test_runVerifyGHAArtifactPath(t *testing.T) {
 
 					outBuilderID, err := cmd.Exec(context.Background(), []string{artifactPath})
 					if !errCmp(err, tt.err) {
-						t.Errorf(cmp.Diff(err, tt.err, cmpopts.EquateErrors()))
+						t.Errorf("%v: %v", v, cmp.Diff(err, tt.err, cmpopts.EquateErrors()))
 					}
 
 					if err != nil {