1.1.0 Stable Release. Update to match firebase_auth v0.18.0

Update to match firebase_auth v0.18.0.
Fix initialization error.
Include initialization test.
Add Readme section explaining why this library isn't needed anymore.

Fixed an initialization error

Updated to match firebase_auth v0.18.0

First stable release

First stable release.
Made some small adjustments to the tests.

Changed the `onAuthStateChangedOrReloaded` to never shutdown

Changed the `onAuthStateChangedOrReloaded` to never shutdown, even if all listeners disconnect, so new listeners in the future can still subscribe.
Modified the tests to include `onAuthStateChangedOrReloaded` new behavior.
Improved the README.

Changed the `onAuthStateChangedOrReloaded` to be a Behavior Subject

Changed the `onAuthStateChangedOrReloaded` to be a Behavior Subject.
Minor modification on the tests.
Improved the README.

Updated the packages, CHANGELOG and improved the README.

Added a pub badge to the README

Added a Testability section to the README