increase node's heap allocation for Netlify builds to go through

Author: fturmel

netlify.toml

@@ -2,6 +2,10 @@
   command = "npm run build-ci"
   # skip build when changes are isolated to README.md or .all-contributorsrc
   ignore = "git diff --quiet HEAD^ HEAD ':(exclude)README.md' ':(exclude).all-contributorsrc' "
+
+[build.environment]
+  NODE_OPTIONS = "--max-old-space-size=4096"
+
 [dev]
   framework = "gatsby"
   targetPort = 8000