Ignore npm-debug.log

Debug log from npm is now ignored

Node.gitignore

@@ -25,3 +25,6 @@ build/Release
 # Dependency directory
 # https://www.npmjs.org/doc/misc/npm-faq.html#should-i-check-my-node_modules-folder-into-git-
 node_modules
+
+# Debug log from npm
+npm-debug.log