Add eslint and solhint

package.json

@@ -20,6 +20,8 @@
     "deploy:apps": "./scripts/every-app.sh \"aragon apm publish major\"",
     "devchain": "aragon devchain --port 7545",
     "dao:address": "truffle exec scripts/current-address.js",
+    "lint:contracts": "solhint contracts/**/*.sol apps/**/contracts/**/*.sol",
+    "lint:wrapper": "eslint lib/",
     "test": "echo \"Error: no test specified\" && exit 1"
   },
   "repository": {
@@ -37,10 +39,15 @@
     "@aragon/kits-base": "^1.0.0",
     "@aragon/os": "^4.1.0",
     "async-each-series": "^1.1.0",
+    "eslint": "^5.16.0",
+    "eslint-plugin-import": "^2.16.0",
+    "eslint-plugin-node": "^8.0.1",
+    "eslint-plugin-promise": "^4.1.1",
     "eth-provider": "^0.2.2",
     "openzeppelin-solidity": "^2.2.0",
     "promptly": "^3.0.3",
-    "solc": "^0.4.25"
+    "solc": "^0.4.25",
+    "solhint": "^2.0.0"
   },
   "dependencies": {
     "ethers": "^4.0.27",