made `update-packages` working directory independent

update-packages.sh

@@ -3,7 +3,7 @@
 set -e
 set -u
 
-pushd packages/assets
+pushd $(cd $(dirname ${0}) && pwd)/packages/assets
 
 OAUTH3_GIT_URL="https://git.daplie.com/Oauth3/oauth3.js.git"
 git clone ${OAUTH3_GIT_URL} org.oauth3 || true
@@ -27,3 +27,5 @@ mkdir -p well-known
 pushd well-known
 ln -snf ../org.oauth3/well-known/oauth3 ./oauth3
 popd
+
+popd