THRIFT-4654 Minor fixes for dart 1 & 2 compatibility (backwards compatible) (#1617)
* THRIFT-4654 Minor fixes for dart 1 & 2 compatibility
* update dockerfiles for CI to test dart 2
* THRIFT-4654 update pubspec for tests
* THRIFT-4654 update dart test generator and readme to 1.24.3
* THRIFT-4654 update generated dart sdk to a range
* fix the dart tutorials
* Add .dart_tool directories to .gitignore
* THRIFT-4654: use dart 2.1.0 and fix cross test dart client timeout
diff --git a/.gitignore b/.gitignore
index b3a5920..82d3d48 100644
--- a/.gitignore
+++ b/.gitignore
@@ -196,6 +196,7 @@
/lib/d/test/transport_test
/lib/d/unittest/
/lib/dart/coverage
+/lib/dart/**/.dart_tool
/lib/dart/**/.packages
/lib/dart/**/packages
/lib/dart/**/.pub/
@@ -305,6 +306,7 @@
/test/cpp/TestServer
/test/csharp/obj
/test/csharp/bin
+/test/dart/**/.dart_tool
/test/dart/**/.packages
/test/dart/**/packages
/test/dart/**/.pub/