chore: Upgrade Babel, Jest, Eslint (#1437)

* chore: Upgrade Prettier 1.8 -> 2.0

* chore: Upgrade Babel 6 -> 7

* chore: Upgrade eslint plugins

* chore: Add eslint import/order rules

* chore: Update flow-typed deps

server/api/middlewares/editor.js

@@ -1,7 +1,7 @@
 // @flow
-import semver from "semver";
 import { type Context } from "koa";
 import pkg from "rich-markdown-editor/package.json";
+import semver from "semver";
 import { EditorUpdateError } from "../../errors";
 
 export default function editor() {

server/api/middlewares/pagination.js

@@ -1,7 +1,7 @@
 // @flow
 import querystring from "querystring";
-import { InvalidRequestError } from "../../errors";
 import { type Context } from "koa";
+import { InvalidRequestError } from "../../errors";
 
 export default function pagination(options?: Object) {
   return async function paginationMiddleware(

server/api/middlewares/pagination.test.js

@@ -5,10 +5,10 @@ import { flushdb, seed } from "../../test/support";
 
 const server = new TestServer(app.callback());
 
-beforeEach(flushdb);
-afterAll(server.close);
+beforeEach(() => flushdb());
+afterAll(() => server.close());
 
-describe("#pagination", async () => {
+describe("#pagination", () => {
   it("should allow offset and limit", async () => {
     const { user } = await seed();
     const res = await server.post("/api/users.list", {