flutter pub update & various fixes (#627)

tool/flutter_pub_upgrade.sh

@@ -4,10 +4,11 @@ set -e
 
 scriptDirectory="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null 2>&1 && pwd )"
 
-for file in `find "${scriptDirectory}/.." -name pubspec.yaml`
+# It seems federated_plugin_* isn't happy to run flutter pub upgrade
+for dir in `find "${scriptDirectory}/.." -name pubspec.yaml -exec dirname {} \; | grep -v federated_plugin | grep -v experimental | sort`
 do
     (
-        cd `dirname $file`
+        cd $dir
         echo "Updating `pwd`"
         flutter pub upgrade
         flutter pub outdated