Update dependencies.

package.json

@@ -30,27 +30,27 @@
     "prepublishOnly": "npm run lint && npm test && npm run build"
   },
   "devDependencies": {
-    "babel-cli": "^6.24.1",
-    "babel-core": "^6.25.0",
-    "babel-eslint": "^7.2.3",
-    "babel-loader": "^7.1.1",
+    "babel-cli": "^6.26.0",
+    "babel-core": "^6.26.0",
+    "babel-eslint": "^8.0.1",
+    "babel-loader": "^7.1.2",
     "babel-preset-env": "^1.6.0",
     "babel-preset-flow": "^6.23.0",
     "babel-preset-stage-0": "^6.24.1",
-    "coveralls": "^2.13.1",
-    "esdoc": "^1.0.1",
+    "coveralls": "^3.0.0",
+    "esdoc": "^1.0.3",
     "esdoc-flow-plugin": "^1.0.0",
     "esdoc-standard-plugin": "^1.0.0",
-    "eslint": "^4.3.0",
-    "eslint-plugin-flowtype": "^2.35.0",
+    "eslint": "^4.8.0",
+    "eslint-plugin-flowtype": "^2.39.1",
     "eslint-plugin-import": "^2.7.0",
     "flow": "^0.2.3",
-    "flow-bin": "^0.52.0",
-    "flow-typed": "^2.1.5",
-    "jest": "^20.0.4",
-    "jest-cli": "^20.0.4",
-    "prettier": "^1.5.3",
-    "webpack": "^3.4.1"
+    "flow-bin": "^0.56.0",
+    "flow-typed": "^2.2.0",
+    "jest": "^21.2.1",
+    "jest-cli": "^21.2.1",
+    "prettier": "^1.7.4",
+    "webpack": "^3.6.0"
   },
   "jest": {
     "moduleDirectories": [