Update .gitignore to new dart_tool pub cache (#40)

bcko · kevmoo · commit 496a262a396f · 2018-07-10T11:30:50.000-07:00
See dart-lang/sdk#32030
diff --git a/.gitignore b/.gitignore
@@ -1,7 +1,3 @@
-*.sw?
-.idea
-.pub
-build
-packages
+.dart_tool/
 .packages
 pubspec.lock
