ionic-framework: Tabs: previousTab() method returns wrong Tab component

Ionic version: [ ] 1.x [x] 2.x

I’m submitting a … [x] bug report [ ] feature request [ ] support request

Current behavior: The previousTab() method from the Tabs component returns the incorrect Tab when called. Currently, it returns the tab that came before the correct one, or null.

Expected behavior: It should always return the most recent Tab component in the selection history that meets the relevant criteria (not hidden, not disabled).

Steps to reproduce:

1. Clone this repo: https://github.com/jsayol/ionic-issue-9999.git
2. Change tabs and watch the information logged out to the console

Related code: The problem seems to be when looping over _selectHistory:

for (var i = this._selectHistory.length - 2; i >= 0; i--) {

should be:

for (var i = this._selectHistory.length - 1; i >= 0; i--) {

Other information: I’m preparing a PR, I want to make sure to update the tests to catch this.

Ionic info:

Your system information:

Cordova CLI: 6.4.0 
Ionic Framework Version: 2.0.0-rc.5
Ionic CLI Version: 2.1.18
Ionic App Lib Version: 2.1.7
Ionic App Scripts Version: 1.0.0
ios-deploy version: Not installed
ios-sim version: Not installed
OS: Linux 4.8
Node Version: v7.4.0
Xcode version: Not installed