(experiment) update brew and use it for create-dmg

.travis.yml

@@ -16,8 +16,10 @@ os: osx
 addons:
   homebrew:
     packages:
+      - create-dmg
       - jq
       - zip
+    update: true
 
 language: node_js
 node_js: "12.14.1"

create_dmg.sh

@@ -4,7 +4,7 @@ set -x
 if [[ "$SHOULD_BUILD" == "yes" ]]; then
   if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then
     cd VSCode-darwin
-    npx create-dmg VSCodium.app ..
+    create-dmg VSCodium.app ..
     mv "../VSCodium ${LATEST_MS_TAG}.dmg" "../VSCodium.${LATEST_MS_TAG}.dmg"
   fi
   cd ..