Fix tests failing in Ubuntu

Some test cases rely on checksum to match in order to pass.
Those checksums were calculated based on file headers which
contain their file modes.

In Ubuntu, the umask is set to 002 by default, resulting in
the tests files having different permissions then when the
same files are cloned on another Linux machine with umask
set to 022.

This change ensures that the files are always set (to 0644 and
the directories to 0755) before running the aforementioned tests.

Signed-off-by: Paulo Gomes <paulo.gomes@weave.works>

controllers/gitrepository_controller_test.go

@@ -919,6 +919,8 @@ func TestGitRepositoryReconciler_reconcileArtifact(t *testing.T) {
 		t.Run(tt.name, func(t *testing.T) {
 			g := NewWithT(t)
 
+			resetChmod(tt.dir, 0o755, 0o644)
+
 			r := &GitRepositoryReconciler{
 				EventRecorder: record.NewFakeRecorder(32),
 				Storage:       testStorage,
@@ -2142,3 +2144,24 @@ func TestGitRepositoryReconciler_calculateContentConfigChecksum(t *testing.T) {
 	artifactCsumModChecksum := r.calculateContentConfigChecksum(obj, artifacts)
 	g.Expect(artifactModChecksum).ToNot(Equal(artifactCsumModChecksum))
 }
+
+func resetChmod(path string, dirMode os.FileMode, fileMode os.FileMode) error {
+	err := filepath.Walk(path,
+		func(path string, info os.FileInfo, err error) error {
+			if err != nil {
+				return err
+			}
+
+			if info.IsDir() && info.Mode() != dirMode {
+				os.Chmod(path, dirMode)
+			} else if !info.IsDir() && info.Mode() != fileMode {
+				os.Chmod(path, fileMode)
+			}
+			return nil
+		})
+	if err != nil {
+		return fmt.Errorf("cannot reset file permissions: %v", err)
+	}
+
+	return nil
+}