Merge pull request #25 from embark-framework/bugfix/check-for-window

Use window for check

src/blockchain.js

@@ -30,7 +30,7 @@ Blockchain.connect = function(connectionList, opts, doneCb) {
   }
 
   const connectWeb3 = async (next) => {
-    if (ethereum) {
+    if (window.ethereum) {
       try {
         await ethereum.enable();
         web3.setProvider(ethereum);