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/middlewares/authentication.js

@@ -1,12 +1,12 @@
 // @flow
+import addMinutes from "date-fns/add_minutes";
+import addMonths from "date-fns/add_months";
 import JWT from "jsonwebtoken";
 import { type Context } from "koa";
-import { User, ApiKey } from "../models";
-import { getUserForJWT } from "../utils/jwt";
-import { getCookieDomain } from "../utils/domains";
 import { AuthenticationError, UserSuspendedError } from "../errors";
-import addMonths from "date-fns/add_months";
-import addMinutes from "date-fns/add_minutes";
+import { User, ApiKey } from "../models";
+import { getCookieDomain } from "../utils/domains";
+import { getUserForJWT } from "../utils/jwt";
 
 export default function auth(options?: { required?: boolean } = {}) {
   return async function authMiddleware(ctx: Context, next: () => Promise<*>) {

server/middlewares/authentication.test.js

@@ -1,13 +1,13 @@
 /* eslint-disable flowtype/require-valid-file-annotation */
-import { flushdb, seed } from "../test/support";
-import { buildUser } from "../test/factories";
-import { ApiKey } from "../models";
 import randomstring from "randomstring";
+import { ApiKey } from "../models";
+import { buildUser } from "../test/factories";
+import { flushdb, seed } from "../test/support";
 import auth from "./authentication";
 
-beforeEach(flushdb);
+beforeEach(() => flushdb());
 
-describe("Authentication middleware", async () => {
+describe("Authentication middleware", () => {
   describe("with JWT", () => {
     it("should authenticate with correct token", async () => {
       const state = {};

server/middlewares/errorHandling.js

@@ -1,7 +1,7 @@
 // @flow
-import Sequelize from "sequelize";
-import { snakeCase } from "lodash";
 import { type Context } from "koa";
+import { snakeCase } from "lodash";
+import Sequelize from "sequelize";
 
 export default function errorHandling() {
   return async function errorHandlingMiddleware(

server/middlewares/methodOverride.js

@@ -1,6 +1,6 @@
 // @flow
-import queryString from "query-string";
 import { type Context } from "koa";
+import queryString from "query-string";
 
 export default function methodOverride() {
   return async function methodOverrideMiddleware(

server/middlewares/validation.js

@@ -1,8 +1,8 @@
 // @flow
-import validator from "validator";
 import { type Context } from "koa";
-import { ParamRequiredError, ValidationError } from "../errors";
+import validator from "validator";
 import { validateColorHex } from "../../shared/utils/color";
+import { ParamRequiredError, ValidationError } from "../errors";
 
 export default function validation() {
   return function validationMiddleware(ctx: Context, next: () => Promise<*>) {