Only run analyze and format on linux (#2513)

Also removed `sudo: false` noop in Travis config
diff --git a/.travis.yml b/.travis.yml
index 2ebbac6..a763fcf 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,5 +1,4 @@
 language: dart
-sudo: false
 
 dart:
   - dev
@@ -27,8 +26,16 @@
   - test: --preset travis `$SPLIT -n l/5/7 .dart_tool/test_files`
   - test: --preset travis `$SPLIT -n l/6/7 .dart_tool/test_files`
   - test: --preset travis `$SPLIT -n l/7/7 .dart_tool/test_files`
-  - dartfmt
-  - dartanalyzer: --fatal-infos --fatal-warnings .
+
+jobs:
+  include:
+  - dart: dev
+    os: linux
+    dart_task: dartfmt
+  - dart: dev
+    os: linux
+    dart_task:
+      dartanalyzer: --fatal-infos --fatal-warnings .
 
 # Create a snapshot to improve startup time. Tests will automatically use this
 # snapshot if it's available.