move wellKnownJson to domains

after some more thought:
* If app moves to another location, user has to remember to move all this config
* It's not really associated with an app. It's to do with the domain info
* We can put some hints in the UI if app is missing.

part of #703

src/routes/domains.js

@@ -99,6 +99,13 @@ function update(req, res, next) {
         if (!req.body.tlsConfig.provider || typeof req.body.tlsConfig.provider !== 'string') return next(new HttpError(400, 'tlsConfig.provider must be a string'));
     }
 
+    if ('wellKnown' in req.body) {
+        if (typeof req.body.wellKnown !== 'object') return next(new HttpError(400, 'wellKnown must be an object'));
+        if (req.body.wellKnown) {
+            if (Object.keys(req.body.wellKnown).some(k => typeof req.body.wellKnown[k] !== 'string')) return next(new HttpError(400, 'wellKnown is a map of strings'));
+        }
+    }
+
     // some DNS providers like DigitalOcean take a really long time to verify credentials (https://github.com/expressjs/timeout/issues/26)
     req.clearTimeout();
 
@@ -107,7 +114,8 @@ function update(req, res, next) {
         provider: req.body.provider,
         config: req.body.config,
         fallbackCertificate: req.body.fallbackCertificate || null,
-        tlsConfig: req.body.tlsConfig || { provider: 'letsencrypt-prod' }
+        tlsConfig: req.body.tlsConfig || { provider: 'letsencrypt-prod' },
+        wellKnown: req.body.wellKnown || null
     };
 
     domains.update(req.params.domain, data, auditSource.fromRequest(req), function (error) {