NEW PROVIDER: NETCUP (DNS) (#718)

* Add support for netcup DNS api.
* Add documentation page.
* Update reference to new version path.
* Add OWNERS entry for netcup.
* Add credentials for integration test. Netcup does not support PTRs. Fix parsing/formating of SRV records.
* Skip integration tests that are not supported.
* Use single quotes in JS code.

integrationTest/integration_test.go

@@ -610,14 +610,15 @@ func makeTests(t *testing.T) []*TestGroup {
 		),
 
 		testgroup("Null MX",
-			not("AZURE_DNS", "GANDI_V5", "NAMEDOTCOM", "DIGITALOCEAN"), // These providers don't support RFC 7505
+			not("AZURE_DNS", "GANDI_V5", "NAMEDOTCOM", "DIGITALOCEAN", "NETCUP"), // These providers don't support RFC 7505
 			tc("Null MX", mx("@", 0, ".")),
 		),
 
 		testgroup("NS",
-			not("DNSIMPLE", "EXOSCALE"),
+			not("DNSIMPLE", "EXOSCALE", "NETCUP"),
 			// DNSIMPLE: Does not support NS records nor subdomains.
 			// EXOSCALE: FILL IN
+			// Netcup: NS records not currently supported.
 			tc("NS for subdomain", ns("xyz", "ns2.foo.com.")),
 			tc("Dual NS for subdomain", ns("xyz", "ns2.foo.com."), ns("xyz", "ns1.foo.com.")),
 			tc("NS Record pointing to @", ns("foo", "**current-domain**")),
@@ -648,7 +649,8 @@ func makeTests(t *testing.T) []*TestGroup {
 			tc("Change a TXT with ws at end", txt("foo", "with space at end  ")),
 		),
 
-		testgroup("empty TXT", not("DNSIMPLE", "CLOUDFLAREAPI"),
+		testgroup("empty TXT",
+			not("DNSIMPLE", "CLOUDFLAREAPI", "NETCUP"),
 			tc("TXT with empty str", txt("foo1", "")),
 			// https://github.com/StackExchange/dnscontrol/issues/598
 			// We decided that permitting the TXT target to be an empty

integrationTest/providers.json

@@ -77,6 +77,12 @@
     "apiuser": "$NAMEDOTCOM_USER",
     "domain": "$NAMEDOTCOM_DOMAIN"
   },
+  "NETCUP": {
+    "api-key": "$NETCUP_KEY",
+    "api-password": "$NETCUP_PASSWORD",
+    "customer-number": "$NETCUP_CUSTOMER_NUMBER",
+    "domain": "$NETCUP_DOMAIN"
+  },
   "NS1": {
     "api_token": "$NS1_TOKEN",
     "domain": "$NS1_DOMAIN"