url_launcher_linux 2.0.0

Linux implementation of the url_launcher plugin.

2.0.0

• Migrate to null safety.
• Update the example app: remove the deprecated RaisedButton and FlatButton widgets.
• Fix outdated links across a number of markdown files (#3276)
• Set implementation in pubspec.yaml

0.0.2+1

• Update Flutter SDK constraint.

0.0.2

• Update integration test examples to use testWidgets instead of test.

0.0.1+4

• Update Dart SDK constraint in example.

0.0.1+3

• Add a missing include.

0.0.1+2

• Check in linux/ directory for example/

0.0.1+1

• README update for endorsement by url_launcher.

0.0.1

• The initial implementation of url_launcher for Linux