Fix newline for denied

This was originally fixed for approved in #12 but the denied case was
missing. This adds a failing test and the fix for it.

approval.go

@@ -147,7 +147,7 @@ func isApproved(commentBody string) (bool, error) {
 
 func isDenied(commentBody string) (bool, error) {
 	for _, deniedWord := range deniedWords {
-		matched, err := regexp.MatchString(fmt.Sprintf("(?i)^%s[.!]?$", deniedWord), commentBody)
+		matched, err := regexp.MatchString(fmt.Sprintf("(?i)^%s[.!]*\n*$", deniedWord), commentBody)
 		if err != nil {
 			return false, err
 		}

approval_test.go

@@ -316,6 +316,11 @@ func TestDeniedCommentBody(t *testing.T) {
 			commentBody: "this is just some random comment",
 			isSuccess:   false,
 		},
+		{
+			name:        "denied_with_newline",
+			commentBody: "denied\n",
+			isSuccess:   true,
+		},
 	}
 
 	for _, testCase := range testCases {