Flutter 1.0.0, updated dependencies, fixed a few bugs to get flutter 1.0.0

[javawolfpack]

Made some updates so it works with flutter 1.0.0:

• Updated flutter dependencies
• Updated Gradle files compile version to 28
• app Gradle target remains 27 due to an issue in flutter stable and form elements: https://github.com/flutter/flutter/issues/21911
• Added subproject workaround to project Gradle to use version 26.1.0 for multidex as it has errors without it: https://github.com/flutter/flutter/issues/14020
• Updated Gradle dependencies

Hope it helps, have found your tutorials a great way to wrap my head around some basic concepts of Flutter.