Improve build time (#1660)

* conditions in build steps

* fix quotes

* remove old code

* refactor step to return true

Author: igorgn

.buildkite/pipeline.yml

@@ -12,14 +12,4 @@ steps:
     - "npm install"
     - "npm run test"
     - "npm run build"
-    key: 'main_build'
-    
-  - label: ":shipit: Publish"
-    depends_on: 'main_build'
-    command:
-    - "nvm install"
-    - "npm install"
-    - "npm run build"
-    - "npm run bkRelease"
-    - "npm run demo"
-    if: "build.pull_request.id == null"
+    - "[[ $BUILDKITE_PULL_REQUEST == 'false' ]] && npm run bkRelease && npm run demo || true"