Update dependencies to enable Greenkeeper 🌴 (#98)

* chore(package): update dependencies

* docs(readme): add Greenkeeper badge

README.md

@@ -2,6 +2,8 @@
 
 # selenium-assistant
 
+[![Greenkeeper badge](https://badges.greenkeeper.io/GoogleChrome/selenium-assistant.svg)](https://greenkeeper.io/)
+
 It can be a challenge to manage which browsers you can / can't run your tests against
 as well as blocking those that have known issues.
 

package.json

@@ -32,8 +32,8 @@
     "chai": "^4.0.2",
     "chromedriver": "^2.30.1",
     "coveralls": "^2.11.12",
-    "eslint": "^3.12.1",
-    "eslint-config-google": "^0.8.0",
+    "eslint": "^4.5.0",
+    "eslint-config-google": "^0.9.1",
     "express": "^4.14.0",
     "firebase": "^4.1.2",
     "geckodriver": "^1.6.0",
@@ -43,18 +43,18 @@
     "mocha": "^3.1.2",
     "operadriver": "^1.0.0",
     "proxyquire": "^1.7.10",
-    "sinon": "^2.1.0"
+    "sinon": "^3.2.1"
   },
   "dependencies": {
-    "chalk": "^1.1.3",
+    "chalk": "^2.1.0",
     "del": "^3.0.0",
     "dmg": "^0.1.0",
-    "fs-extra": "^3.0.1",
+    "fs-extra": "^4.0.1",
     "mkdirp": "^0.5.1",
     "node-localstorage": "^1.3.0",
     "request": "^2.78.0",
     "sauce-connect-launcher": "^1.0.0",
-    "selenium-webdriver": "3.4.0",
+    "selenium-webdriver": "3.5.0",
     "semver": "^5.3.0",
     "which": "^1.2.11",
     "yauzl": "^2.7.0"