Ignore commits on the gh-pages branch for CI

Commits to gh-pages "fail" on CircleCI since there's no config on the branch. Skip these commits using a tag I can't write here because I do want CI to run on this commit :)

package.json

@@ -6,7 +6,7 @@
   "scripts": {
     "build": "npm run clean && webpack --progress --colors --bail",
     "clean": "rimraf ./build && mkdirp build && rimraf ./dist && mkdirp dist",
-    "deploy": "touch build/.nojekyll && gh-pages -t -d build -m \"Build for $(git log --pretty=format:%H -n1)\"",
+    "deploy": "touch build/.nojekyll && gh-pages -t -d build -m \"Build for $(git log --pretty=format:%H -n1) [skip ci]\"",
     "prune": "./prune-gh-pages.sh",
     "i18n:push": "tx-push-src scratch-editor interface translations/en.json",
     "i18n:src": "rimraf ./translations/messages/src && babel src > tmp.js && rimraf tmp.js && build-i18n-src ./translations/messages/src ./translations/ && npm run i18n:push",