test(pageObjects): Added rxEnvironment Page Object

Added a page object for rxEnvironment. getEnv returns the current environment.
@parlarjb https://github.com/Droogans/encore-ui/commit/ce609ca7a2cbbc901a84399547e996517c5256a2

@TheNando https://github.com/Droogans/encore-ui/commit/865d020ca8b705a6c0b813374015d7fcf331106c