feat: enable eslint

.eslintrc

+{
+  "extends" : [
+    "standard",
+    "plugin:promise/recommended"
+  ],
+  "plugins": [
+    "promise"
+  ],
+  "env": {
+    "browser" : true,
+    "node"    : true,
+    "mocha"   : true,
+    "jest"    : true
+  },
+  "globals" : {
+    "artifacts": false,
+    "contract": false,
+    "assert": false,
+    "web3": false
+  },
+  "rules": {
+
+    // Strict mode
+    "strict": [2, "global"],
+
+    // Code style
+    "indent": [2, 2],
+    "quotes": [2, "single"],
+    "no-use-before-define": 0,
+    "eqeqeq": [2, "smart"],
+    "dot-notation": [2, {"allowKeywords": true, "allowPattern": ""}],
+    "no-redeclare": [2, {"builtinGlobals": true}],
+    "no-trailing-spaces": [2, { "skipBlankLines": true }],
+    "eol-last": 1,
+    "comma-spacing": [2, {"before": false, "after": true}],
+    "camelcase": [2, {"properties": "always"}],
+    "no-mixed-spaces-and-tabs": [2, "smart-tabs"],
+    "comma-dangle": [1, "always-multiline"],
+    "no-dupe-args": 2,
+    "no-dupe-keys": 2,
+    "no-debugger": 0,
+    "no-undef": 2,
+    "object-curly-spacing": [2, "always"],
+    "max-len": [2, 120, 2],
+    "generator-star-spacing": ["error", "before"],
+    "promise/avoid-new": 0,
+    "promise/always-return": 0
+  }
+}

package.json

@@ -35,8 +35,14 @@
     "chai-as-promised": "^7.0.0",
     "chai-bignumber": "^2.0.0",
     "coveralls": "^2.13.1",
-    "ethereumjs-util": "^5.1.2",
+    "eslint": "^4.11.0",
+    "eslint-config-standard": "^10.2.1",
+    "eslint-plugin-import": "^2.8.0",
+    "eslint-plugin-node": "^5.2.1",
+    "eslint-plugin-promise": "^3.6.0",
+    "eslint-plugin-standard": "^3.0.1",
     "ethereumjs-testrpc": "^6.0.1",
+    "ethereumjs-util": "^5.1.2",
     "mocha-lcov-reporter": "^1.3.0",
     "solidity-coverage": "^0.2.2",
     "truffle": "^4.0.0",

test/.eslintrc

+{
+    "rules": {
+        "no-unused-expressions": 0
+    }
+}