Operator optional (#22361)

Operator optional and fix type "time mysql"

DOC mysql: https://dev.mysql.com/doc/refman/5.7/en/date-and-time-functions.html#function_time
TIME(expr)

Extracts the time part of the time or datetime expression expr and returns it as a string.

This function is unsafe for statement-based replication. A warning is logged if you use this function when binlog_format is set to STATEMENT.

src/Illuminate/Database/Query/Builder.php

@@ -993,12 +993,16 @@ public function orWhereDate($column, $operator, $value)
      *
      * @param  string  $column
      * @param  string   $operator
-     * @param  int   $value
+     * @param  string   $value
      * @param  string   $boolean
      * @return \Illuminate\Database\Query\Builder|static
      */
-    public function whereTime($column, $operator, $value, $boolean = 'and')
+    public function whereTime($column, $operator, $value = null, $boolean = 'and')
     {
+        list($value, $operator) = $this->prepareValueAndOperator(
+            $value, $operator, func_num_args() == 2
+        );
+
         return $this->addDateBasedWhere('Time', $column, $operator, $value, $boolean);
     }