fix: add default message for isMilitaryTime validator (#411)

Close #287

Author: Kiliandeca

Diff for: src/validation/ValidationTypes.ts

@@ -261,7 +261,9 @@ export class ValidationTypes {
                 return eachPrefix + "$property must be shorter than or equal to $constraint1 characters";
             case this.MATCHES:
                 return eachPrefix + "$property must match $constraint1 regular expression";
-
+            case this.IS_MILITARY_TIME:
+                return eachPrefix + "$property must be a valid representation of military time in the format HH:MM";
+                
             /* array checkers */
             case this.ARRAY_CONTAINS:
                 return eachPrefix + "$property must contain $constraint1 values";