fix(start): use spawn instead of exec

lib/start.js

@@ -48,20 +48,29 @@ var V2_STARTERS = {
   tutorial: { "repoName": "ionic2-starter-tutorial" }
 }
 
-Start.runExecCommand = function runExecCommand(command) {
+Start.runSpawnCommand = function runSpawnCommand(cmd, args) {
   var q = Q.defer();
+  var command = cmd + args.join(' ');
   var childProcess = require('child_process');
 
   logging.logger.debug('Running exec command:', command);
 
-  childProcess.exec(command, function(err, stdout, stderr) {
-    if (err) {
-      Utils.fail('Unable to run exec command' + err);
-      q.reject(err);
-    } else {
-      logging.logger.debug('Completed', stdout);
-      q.resolve(stdout);
+  var spawned = childProcess.spawn(cmd, args);
+  spawned.on('error', function(err){
+    Utils.fail('Unable to run spawn command' + err);
+  })
+  spawned.stdout.on('data', function(data){
+    logging.logger.debug(data.toString());
+  });
+  spawned.stderr.on('data', function(data){
+    logging.logger.debug(data.toString());
+  });
+  spawned.on('exit', function(code){
+    logging.logger.debug('Spawn command completed');
+    if (code !== 0) {
+      return q.reject('There was an error with the spawned command: ' + command);
     }
+    return q.resolve();
   });
 
   return q.promise;
@@ -99,7 +108,7 @@ Start.startApp = function startApp(options) {
   .then(function() {
     if (!options.skipNpm) {
       logging.logger.info('Installing npm packages...'.green);
-      return Start.runExecCommand('npm install');
+      return Start.runSpawnCommand('npm', ['install']);
     }
   })
   .then(function(){