Update 6.3 solution to match code from 6.2

Putnam14 · marijnh · commit 34c6ca611243 · 2018-06-24T17:11:14.000+02:00
In the solution for 6.2 you used the 'this.has(value)' method, instead of 'this.members.includes(value)' in the 'add(value)' method.

The code should be consistent considering the exercise says:
// Your code here (and the code from the previous exercise)
diff --git a/code/solutions/06_3_iterable_groups.js b/code/solutions/06_3_iterable_groups.js
@@ -4,7 +4,7 @@ class Group {
   }
 
   add(value) {
-    if (!this.members.includes(value)) {
+    if (!this.has(value)) {
       this.members.push(value);
     }
   }

Original file line number	Diff line number	Diff line change
`@@ -4,7 +4,7 @@ class Group {`
`4`	`4`	`}`
`5`	`5`
`6`	`6`	`add(value) {`
`7`		`- if (!this.members.includes(value)) {`
	`7`	`+ if (!this.has(value)) {`
`8`	`8`	`this.members.push(value);`
`9`	`9`	`}`
`10`	`10`	`}`