Use recommended analysis_options name, support Dart v2-dev, test on FF (flutter#9)

Author: kevmoo

.travis.yml

@@ -8,6 +8,7 @@ cache:
     - $HOME/.pub-cache
 dart_task:
   - test: --platform vm
+  - test: --platform firefox
   - test: --platform dartium
     install_dartium: true
   - dartanalyzer

.analysis_options analysis_options.yaml.analysis_options renamed to analysis_options.yaml

@@ -1,11 +1,11 @@
 name: convert
-version: 2.0.1
+version: 2.0.2-dev
 description: Utilities for converting between data representations.
 author: Dart Team <[email protected]>
 homepage: https://github.com/dart-lang/convert
 
 environment:
-  sdk: '>=1.17.0-dev.6.2 <2.0.0'
+  sdk: '>=1.17.0 <2.0.0-dev.infinity'
 
 dependencies:
   charcode: '^1.1.0'