test(pageObjects): Added rxEnvironment Page Object

Added a page object for rxEnvironment. getEnv returns the current environment.
I like the one that uses { UseBaseUrl: true }

Also...
```
environments: _.defaults(_.clone(browser.params.environments) || {}, {
        'localhost': 'localhost',
        'staging': 'staging',
        'preprod': 'preprod'
    }),
```
could be
```
environments: _.extend({
        'localhost': 'localhost',
        'staging': 'staging',
        'preprod': 'preprod'
    }, browser.params.environments),
```
That should not only save you the clone, but also handing the undefined or null cases.