chore(deps) update deps

Author: Jerome Houdan

.gitignore

@@ -3,5 +3,6 @@ node_modules
 .DS_Store
 npm-debug.log
 coverage
+package-lock.json
 
 yarn.lock

package.json

@@ -33,21 +33,21 @@
     "babel-preset-es2015": "^6.22.0",
     "babel-preset-stage-0": "^6.22.0",
     "babel-register": "^6.22.0",
-    "chai": "^3.5.0",
     "eslint": "^2.9.0",
     "eslint-config-zavatta": "^3.0.1",
     "eslint-plugin-import": "^1.6.1",
-    "mocha": "^2.4.5",
     "sinon": "^1.17.5"
   },
   "dependencies": {
     "babel-runtime": "^6.22.0",
+    "chai": "^4.1.2",
     "form-data": "^1.0.1",
     "lodash": "^4.12.0",
+    "mocha": "^5.1.0",
     "nock": "^8.0.0",
-    "superagent": "^2.3.0",
+    "superagent": "^3.8.2",
     "superagent-promise": "^1.1.0",
-    "superagent-proxy": "^1.0.1"
+    "superagent-proxy": "^1.0.3"
   },
   "babel": {
     "presets": [