set up gsn provider for coverage too

truffle-config.js

@@ -12,24 +12,28 @@ const solcNightly = {
 
 const useSolcNightly = process.env.SOLC_NIGHTLY === 'true';
 
-module.exports = {
-  networks: {
-    development: {
-      provider: new GSNDevProvider('http://localhost:8545', {
+function getProvider(url, options) {
+  return new GSNDevProvider('http://localhost:8545', Object.assign({
     txfee: 70,
     useGSN: false,
     // The last two accounts defined in test.sh
     ownerAddress: '0x26be9c03ca7f61ad3d716253ee1edcae22734698',
     relayerAddress: '0xdc5fd04802ea70f6e27aec12d56716624c98e749',
-      }),
+  }, options));
+}
+
+module.exports = {
+  networks: {
+    development: {
+      provider: getProvider('http://localhost:8545'),
       network_id: '*', // eslint-disable-line camelcase
     },
     coverage: {
-      host: 'localhost',
-      network_id: '*', // eslint-disable-line camelcase
-      port: 8555,
+      provider: getProvider('http://localhost:8555', {
         gas: 0xfffffffffff,
         gasPrice: 0x01,
+      }),
+      network_id: '*', // eslint-disable-line camelcase
     },
   },