Upgrade jest.

package.json

@@ -12,7 +12,7 @@
     "autoprefixer": "^7.2.6",
     "babel-cli": "^6.26.0",
     "babel-core": "^6.26.3",
-    "babel-jest": "^22.4.4",
+    "babel-jest": "^23.4.0",
     "babel-plugin-transform-object-assign": "^6.22.0",
     "babel-plugin-transform-object-rest-spread": "^6.26.0",
     "babel-plugin-transform-proto-to-assign": "^6.26.0",
@@ -36,7 +36,7 @@
     "eslint-config-standard-preact": "^1.1.6",
     "eslint-plugin-compat": "^2.4.0",
     "eslint-plugin-import": "^2.13.0",
-    "eslint-plugin-jest": "^21.17.0",
+    "eslint-plugin-jest": "^21.18.0",
     "eslint-plugin-node": "^4.2.3",
     "eslint-plugin-promise": "^3.8.0",
     "eslint-plugin-standard": "^3.1.0",
@@ -46,7 +46,7 @@
     "glob": "^7.1.2",
     "gzip-size": "^5.0.0",
     "isomorphic-fetch": "2.2.1",
-    "jest": "^22.4.4",
+    "jest": "^23.4.1",
     "json3": "^3.3.2",
     "lerna": "^2.11.0",
     "lint-staged": "^6.1.1",