Use the latest available Flutter image

Plus run `flutter analyze`
diff --git a/packages/flutter_markdown/.cirrus.yml b/packages/flutter_markdown/.cirrus.yml
index fe11138..0505d8a 100644
--- a/packages/flutter_markdown/.cirrus.yml
+++ b/packages/flutter_markdown/.cirrus.yml
@@ -1,7 +1,12 @@
 container:
-  image: cirrusci/flutter:0.1.0
+  image: cirrusci/flutter:latest
 
 test_task:
   pub_cache:
     folder: ~/.pub-cache
-  test_script: flutter test
\ No newline at end of file
+  test_script: flutter test
+
+analyze_task:
+  pub_cache:
+    folder: ~/.pub-cache
+  analyze_script: flutter analyze
\ No newline at end of file