title: Should I unsubscribe when using rxbinding?
body: <p>There is how I use RxBinding with Kotlin:</p>
  
  <pre><code>override fun onViewCreated(view: View?, savedInstanceState: Bundle?) {
      super.onViewCreated(view, savedInstanceState)
      reset_password_text_view.clicks().subscribe { presenter.showConfirmSecretQuestionBeforeResetPassword() }
      password_edit_text.textChanges().skip(1).subscribe { presenter.onPasswordChanged(it.toString()) }
      password_edit_text.editorActionEvents().subscribe { presenter.done(password_edit_text.text.toString()) }
  }
  </code></pre>
  
  <p><code>Observable.subscribe(action)</code> returns <code>Subscription</code>. Should I keep it as reference and unsubscribe <code>onPause()</code> or <code>onDestroy()</code>?</p>
  
  <p>Like this:</p>
  
  <pre><code>private lateinit var resetPasswordClicksSubs: Subscription
  
  override fun onViewCreated(view: View?, savedInstanceState: Bundle?) {
      super.onViewCreated(view, savedInstanceState)
      resetPasswordClicksSubs = reset_password_text_view.clicks().subscribe { presenter.showConfirmSecretQuestionBeforeResetPassword() }
  }
  
  override fun onDestroy() {
      super.onDestroy()
      resetPasswordClicksSubs.unsubscribe()
  }
  </code></pre>