Add eslint for testsuits

tests/.eslintrc

@@ -0,0 +1,29 @@
+{
+  "parser": "babel-eslint",
+  "extends": "eslint:recommended",
+  "env": {
+    "browser": true,
+    "mocha": true
+  },
+  "globals": {
+    "should": true,
+    "expect": true
+  },
+  "rules": {
+    "quotes": [2, "single"],
+    "no-console": 0,
+    "comma-spacing": 2,
+    "comma-style": [2, "last"],
+    "consistent-return": 2,
+    "strict": [2, "global"],
+    "eqeqeq": [2, "smart"],
+    "curly": [2, "multi-line"],
+    "semi-spacing": [2, {"before": false, "after": true}],
+    "semi": [2, "always"],
+    "no-extra-semi": 2,
+    "comma-dangle": [2, "never"],
+    "no-sequences": 2,
+    "comma-spacing": [2, {"before": false, "after": true}],
+    "comma-style": [2, "last"]
+  }
+}