remove unused exceljs from client bundle

models/runOnServer.js

@@ -0,0 +1,8 @@
+/**
+ * Executes a function only if we are on the server. Use in combination
+ * with package-sepcific loader functions to create a "nested" import that
+ * prevents leakage of server-dependencies to the client.
+ * @param fct {function} the function to be executed on the server
+ * @return {*} a return value from the function, if there is any
+ */
+export const runOnServer = fct => Meteor.isServer && fct();