Create a updated instance of mem-fs-editor

Author: mshima

lib/index.js

@@ -220,13 +220,7 @@ class Generator extends EventEmitter {
       }
     }
 
-    try {
-      this.fs = this.env.fs || require('mem-fs-editor').create(this.env.sharedFs);
-    } catch (_) {
-      throw new Error(
-        "Current environment don't provides some necessary feature this generator needs"
-      );
-    }
+    this.fs = require('mem-fs-editor').create(this.env.sharedFs);
 
     this.description = this.description || '';