Move minitest.dart into the expect package.

pkg/dev_compiler/tool/build_test_pkgs.sh

 #!/bin/bash
 set -e # bail on error
 
 cd $( dirname "${BASH_SOURCE[0]}" )/..
 
 mkdir -p gen/codegen_output/pkg/
 
 SDK=--dart-sdk-summary=lib/js/amd/dart_sdk.sum
 
 ./bin/dartdevc.dart $SDK -o gen/codegen_output/pkg/expect.js \
-    package:expect/expect.dart
+    package:expect/expect.dart \
+    package:expect/minitest.dart
 
 ./bin/dartdevc.dart $SDK -o gen/codegen_output/pkg/async_helper.js \
     --url-mapping=package:async_helper/async_helper.dart,test/codegen/async_helper.dart \
     package:async_helper/async_helper.dart
 
-./bin/dartdevc.dart $SDK -o gen/codegen_output/pkg/minitest.js \
-    --url-mapping=package:minitest/minitest.dart,test/codegen/minitest.dart \
-    package:minitest/minitest.dart
-
 ./bin/dartdevc.dart $SDK -o gen/codegen_output/pkg/js.js \
     package:js/js.dart
 
 ./bin/dartdevc.dart $SDK -o gen/codegen_output/pkg/matcher.js \
     package:matcher/matcher.dart
 
 ./bin/dartdevc.dart $SDK -o gen/codegen_output/pkg/path.js \
     package:path/path.dart
 
 ./bin/dartdevc.dart $SDK -o gen/codegen_output/pkg/stack_trace.js \
     -s gen/codegen_output/pkg/path.sum \
     package:stack_trace/stack_trace.dart
 
 ./bin/dartdevc.dart $SDK --unsafe-force-compile \
     -o gen/codegen_output/pkg/unittest.js \
     -s gen/codegen_output/pkg/matcher.sum \
     -s gen/codegen_output/pkg/path.sum \
     -s gen/codegen_output/pkg/stack_trace.sum \
     package:unittest/unittest.dart \
     package:unittest/html_config.dart \
     package:unittest/html_individual_config.dart \
     package:unittest/html_enhanced_config.dart