Update process spawning in coverage.js for mocha 2.2.x

package.json

@@ -61,7 +61,7 @@
     "cross-spawn": "^0.2.6",
     "jscoverage": "^0.5.9",
     "jshint": "^2.6.3",
-    "mocha": "^2.2.0",
+    "mocha": "^2.2.1",
     "mocha-lcov-reporter": "^0.0.2"
   }
 }

scripts/coverage.js

@@ -12,7 +12,9 @@ function suite() {
   process.env.NODESASS_COV = 1;
 
   var coveralls = spawn(bin('coveralls'));
-  var mocha = spawn(bin('_mocha'), ['--reporter', 'mocha-lcov-reporter'], {
+
+  var args = [bin('_mocha')].concat(['--reporter', 'mocha-lcov-reporter']);
+  var mocha = spawn(process.execPath, args, {
     env: process.env
   });