replace router.push with router.replace

with replace you can't return to the previous page which is what we want after a
form.

src/pages/coaches/CoachRegistration.vue

@@ -14,7 +14,7 @@ export default {
   methods: {
     saveData(data) {
       this.$store.dispatch('coaches/registerCoach', data);
-      this.$router.push('/coaches');
+      this.$router.replace('/coaches');
     }
   }
 };