Allows Secret & ConfigMap Keys to look like Environment Variables

This makes environment variable style keys (uppercase with underscores) valid
in Secrets and ConfigMap.

pkg/util/validation/validation_test.go

@@ -377,11 +377,14 @@ func TestIsValidPercent(t *testing.T) {
 
 func TestIsConfigMapKey(t *testing.T) {
 	successCases := []string{
+		"a",
 		"good",
 		"good-good",
 		"still.good",
 		"this.is.also.good",
 		".so.is.this",
+		"THIS_IS_GOOD",
+		"so_is_this_17",
 	}
 
 	for i := range successCases {
@@ -391,14 +394,16 @@ func TestIsConfigMapKey(t *testing.T) {
 	}
 
 	failureCases := []string{
-		"bad_bad",
+		".",
+		"..",
 		"..bad",
-		"bad.",
+		"b*d",
+		"bad!&bad",
 	}
 
 	for i := range failureCases {
 		if errs := IsConfigMapKey(failureCases[i]); len(errs) == 0 {
-			t.Errorf("[%d] expected success", i)
+			t.Errorf("[%d] expected failure", i)
 		}
 	}
 }