[Examples] Add SWR to api-routes and api-routes-middleware

[lfades]

The current examples are using getServerSideProps with API Routes, which has the following downsides:

• The ZEIT Now deployment doesn't work because it uses an absolute URL to localhost. (And relative URLs only work for the browser)
• It adds SSR to an use case where it's not required

Client side data fetching fixes the above issues, the use case could still be better for SSG, but the idea of this examples is to show the usage of API Routes. We could change them in the future to do actions instead of data loading, but for the moment this is a good fix.

[ijjk]

Stats from current PR

Default Server Mode

General

	zeit/next.js canary	lfades/next.js examples/api-routes-swr	Change
buildDuration	10.4s	10.2s	-251ms
nodeModulesSize	53.1 MB	53.1 MB	✓

Client Bundles (main, webpack, commons)

	zeit/next.js canary	lfades/next.js examples/api-routes-swr	Change
main-HASH.js gzip	6.24 kB	6.24 kB	✓
webpack-HASH.js gzip	746 B	746 B	✓
de003c3a9d30..c6c1.js gzip	10.1 kB	10.1 kB	✓
framework.HASH.js gzip	39.1 kB	39.1 kB	✓
Overall change	56.2 kB	56.2 kB	✓

Client Bundles (main, webpack, commons) Modern

	zeit/next.js canary	lfades/next.js examples/api-routes-swr	Change
main-HASH.module.js gzip	4.77 kB	4.77 kB	✓
webpack-HASH..dule.js gzip	746 B	746 B	✓
de003c3a9d30..dule.js gzip	6.71 kB	6.71 kB	✓
framework.HA..dule.js gzip	39.1 kB	39.1 kB	✓
Overall change	51.4 kB	51.4 kB	✓

Legacy Client Bundles (polyfills)

	zeit/next.js canary	lfades/next.js examples/api-routes-swr	Change
polyfills-HASH.js gzip	26.3 kB	26.3 kB	✓
Overall change	26.3 kB	26.3 kB	✓

Client Pages

	zeit/next.js canary	lfades/next.js examples/api-routes-swr	Change
_app.js gzip	1.24 kB	1.24 kB	✓
_error.js gzip	3.15 kB	3.15 kB	✓
hooks.js gzip	664 B	664 B	✓
index.js gzip	222 B	222 B	✓
link.js gzip	2.03 kB	2.03 kB	✓
routerDirect.js gzip	279 B	279 B	✓
withRouter.js gzip	278 B	278 B	✓
Overall change	7.86 kB	7.86 kB	✓

Client Pages Modern

	zeit/next.js canary	lfades/next.js examples/api-routes-swr	Change
_app.module.js gzip	594 B	594 B	✓
_error.module.js gzip	2.08 kB	2.08 kB	✓
hooks.module.js gzip	370 B	370 B	✓
index.module.js gzip	212 B	212 B	✓
link.module.js gzip	1.48 kB	1.48 kB	✓
routerDirect..dule.js gzip	271 B	271 B	✓
withRouter.m..dule.js gzip	270 B	270 B	✓
Overall change	5.28 kB	5.28 kB	✓

Client Build Manifests

	zeit/next.js canary	lfades/next.js examples/api-routes-swr	Change
_buildManifest.js gzip	61 B	61 B	✓
_buildManife..dule.js gzip	61 B	61 B	✓
Overall change	122 B	122 B	✓

Rendered Page Sizes

	zeit/next.js canary	lfades/next.js examples/api-routes-swr	Change
index.html gzip	917 B	917 B	✓
link.html gzip	925 B	925 B	✓
withRouter.html gzip	915 B	915 B	✓
Overall change	2.76 kB	2.76 kB	✓

---

Serverless Mode (Decrease detected ✓)

General

	zeit/next.js canary	lfades/next.js examples/api-routes-swr	Change
buildDuration	11.3s	11.3s	-10ms
nodeModulesSize	53.1 MB	53.1 MB	✓

Client Bundles (main, webpack, commons)

	zeit/next.js canary	lfades/next.js examples/api-routes-swr	Change
main-HASH.js gzip	6.24 kB	6.24 kB	✓
webpack-HASH.js gzip	746 B	746 B	✓
de003c3a9d30..c6c1.js gzip	10.1 kB	10.1 kB	✓
framework.HASH.js gzip	39.1 kB	39.1 kB	✓
Overall change	56.2 kB	56.2 kB	✓

Client Bundles (main, webpack, commons) Modern

	zeit/next.js canary	lfades/next.js examples/api-routes-swr	Change
main-HASH.module.js gzip	4.77 kB	4.77 kB	✓
webpack-HASH..dule.js gzip	746 B	746 B	✓
de003c3a9d30..dule.js gzip	6.71 kB	6.71 kB	✓
framework.HA..dule.js gzip	39.1 kB	39.1 kB	✓
Overall change	51.4 kB	51.4 kB	✓

Legacy Client Bundles (polyfills)

	zeit/next.js canary	lfades/next.js examples/api-routes-swr	Change
polyfills-HASH.js gzip	26.3 kB	26.3 kB	✓
Overall change	26.3 kB	26.3 kB	✓

Client Pages

	zeit/next.js canary	lfades/next.js examples/api-routes-swr	Change
_app.js gzip	1.24 kB	1.24 kB	✓
_error.js gzip	3.15 kB	3.15 kB	✓
hooks.js gzip	664 B	664 B	✓
index.js gzip	222 B	222 B	✓
link.js gzip	2.03 kB	2.03 kB	✓
routerDirect.js gzip	279 B	279 B	✓
withRouter.js gzip	278 B	278 B	✓
Overall change	7.86 kB	7.86 kB	✓

Client Pages Modern

	zeit/next.js canary	lfades/next.js examples/api-routes-swr	Change
_app.module.js gzip	594 B	594 B	✓
_error.module.js gzip	2.08 kB	2.08 kB	✓
hooks.module.js gzip	370 B	370 B	✓
index.module.js gzip	212 B	212 B	✓
link.module.js gzip	1.48 kB	1.48 kB	✓
routerDirect..dule.js gzip	271 B	271 B	✓
withRouter.m..dule.js gzip	270 B	270 B	✓
Overall change	5.28 kB	5.28 kB	✓

Client Build Manifests

	zeit/next.js canary	lfades/next.js examples/api-routes-swr	Change
_buildManifest.js gzip	61 B	61 B	✓
_buildManife..dule.js gzip	61 B	61 B	✓
Overall change	122 B	122 B	✓

Serverless bundles Overall decrease ✓

	zeit/next.js canary	lfades/next.js examples/api-routes-swr	Change
_error.js gzip	294 kB	294 kB	-901 B
404.html gzip	1.32 kB	1.32 kB	✓
hooks.html gzip	958 B	958 B	✓
index.js gzip	294 kB	293 kB	-796 B
link.js gzip	302 kB	302 kB	-385 B
routerDirect.js gzip	300 kB	300 kB	-79 B
withRouter.js gzip	300 kB	300 kB	⚠️ +659 B
Overall change	1.49 MB	1.49 MB	-1.5 kB