Fix skipping of '__tests__' folder during Babel build

package.json

@@ -39,7 +39,7 @@
     "lint": "eslint src",
     "prettier": "prettier --write 'src/**/*.js'",
     "check": "flow check",
-    "build": "rm -rf dist/* && babel src --ignore __tests__ --out-dir dist && npm run build:flow",
+    "build": "rm -rf dist/* && babel src --ignore '**/__tests__' --out-dir dist && npm run build:flow",
     "build:flow": "find ./src -name '*.js' -not -path '*/__tests__*' | while read filepath; do cp $filepath `echo $filepath | sed 's/\\/src\\//\\/dist\\//g'`.flow; done",
     "watch": "node resources/watch.js",
     "cover": "nyc npm run testonly",