Allow endpoint to be configured (for the tests)

src/routes/test/settings-test.js

@@ -265,7 +265,7 @@ describe('Settings API', function () {
                    .query({ access_token: token })
                    .end(function (err, res) {
                 expect(res.statusCode).to.equal(200);
-                expect(res.body).to.eql({ provider: 'route53', accessKeyId: 'accessKey', secretAccessKey: 'secretAccessKey', region: 'us-east-1' });
+                expect(res.body).to.eql({ provider: 'route53', accessKeyId: 'accessKey', secretAccessKey: 'secretAccessKey', region: 'us-east-1', endpoint: null });
                 done(err);
             });
         });

src/settings.js

@@ -235,7 +235,8 @@ function setDnsConfig(dnsConfig, callback) {
         provider: dnsConfig.provider,
         accessKeyId: dnsConfig.accessKeyId,
         secretAccessKey: dnsConfig.secretAccessKey,
-        region: dnsConfig.region || 'us-east-1'
+        region: dnsConfig.region || 'us-east-1',
+        endpoint: dnsConfig.endpoint || null
     };
 
     settingsdb.set(exports.DNS_CONFIG_KEY, JSON.stringify(credentials), function (error) {