chore: use server instead of backend

packages/client/test/components/actions.test.js

@@ -14,7 +14,7 @@ describe('component actions combiner', () => {
         },
       },
       {
-        backend: "don't care",
+        server: "don't care",
       },
     ]
     const actions = require('../../src/components/actions')

packages/client/test/components/reducers.test.js

@@ -21,7 +21,7 @@ describe('component actions combiner', () => {
         },
       },
       {
-        backend: "don't care",
+        server: "don't care",
       },
     ]
     const reducers = require('../../src/components/reducers')

packages/components/AWSS3-server/index.js

 require('dotenv').config()
 
 module.exports = {
-  backend: () => app => require('./src/FileBackend')(app),
+  server: () => app => require('./src/FileBackend')(app),
 }

packages/components/Epub/index.js

 module.exports = {
-  backend: () => app => require('./EpubBackend')(app),
+  server: () => app => require('./EpubBackend')(app),
 }

packages/components/Ink-server/index.js

 module.exports = {
-  backend: () => app => require('./InkBackend')(app),
+  server: () => app => require('./InkBackend')(app),
 }

packages/components/PasswordReset-server/index.js

 module.exports = {
-  backend: () => app => require('./PasswordResetBackend')(app),
+  server: () => app => require('./PasswordResetBackend')(app),
 }

packages/components/xpub-review-server/src/index.js

 module.exports = {
-  backend: () => require('./reviewBackend.js'),
+  server: () => require('./reviewBackend.js'),
 }

packages/server/test/mocks/mock_component.js

 const STATUS = require('http-status-codes')
 
 const mockComponent = {
-  backend: () => app => {
+  server: () => app => {
     app.use('/mock-component', (req, res, next) =>
       res.status(STATUS.OK).json({ ok: '!' }),
     )