fix 覆盖率文件对应编译后的es6文件

Author: laiyuandong

package.json

@@ -68,14 +68,14 @@
     "get-pixels": "^3.3.0",
     "images": "^3.0.0",
     "imports-loader": "^0.7.0",
-    "istanbul": "^0.4.5",
+    "istanbul": "gotwarlost/istanbul.git#source-map",
     "jasmine-core": "^2.5.2",
     "jsdoc": "^3.5.4",
     "karma": "^1.4.1",
     "karma-browserify": "^5.1.1",
     "karma-chrome-launcher": "^2.0.0",
     "karma-cli": "^1.0.1",
-    "karma-coverage": "^1.1.1",
+    "karma-coverage": "douglasduteil/karma-coverage#next",
     "karma-jasmine": "^1.1.0",
     "karma-teamcity-reporter": "^1.0.0",
     "leaflet": "1.0.3",