Using 'ionic generate tabs' produces invalid ngModule with tab

**Description:**
ionic generate tabs issue

When we generate tabs, the main tab module contains also dependency after the first tab. It generates Angular error because one Angular component cannot be used in two different modules with the same name.

Here is the code for tabs page with not needed reference to FirstPage component
```
import { NgModule } from '@angular/core';
import { IonicPageModule } from 'ionic-angular';
import { TabyPage } from './taby';
import { FirstPage } from '../first/first';

@NgModule({
declarations: [
TabyPage,
FirstPage, // this component should NOT be here
],
imports: [
IonicPageModule.forChild(TabyPage),
]
})
export class TabyPageModule {}
```

**My `ionic info`:**

global packages:

@ionic/cli-utils : 1.4.0
Ionic CLI : 3.4.0

local packages:

@ionic/app-scripts : 1.3.7
@ionic/cli-plugin-ionic-angular : 1.3.0
Ionic Framework : ionic-angular 3.3.0

System:

Node : v6.9.5
OS : Linux 4.4
Xcode : not installed
ios-deploy : not installed
ios-sim : not installed
npm : 3.10.10