ci(travis): Fix bundlesize task.

Author: Jay Freestone

.travis.yml

@@ -2,20 +2,23 @@ language: node_js
 node_js:
   - 10
 cache:
+  # Caches $HOME/.npm when npm ci is default script command
+  # Caches node_modules in all other cases
+  npm: true
   directories:
-    - "$HOME/.npm"
+    # we also need to cache folder with Cypress binary
+    - ~/.cache
 jobs:
   include:
     - stage: test
       before_script: npm run build
       script: npm run test:ci
     - before_script: npm run build
-      script: npm run bundlesize
+      script: npx bundlesize
     - stage: release
       before_script: npm run build
       script: skip
       deploy:
         provider: script
         skip_cleanup: true
-        script:
-          - npx semantic-release
+        script: npx semantic-release