fix: add trailing / to endpoint

Closes #2363

lib/util/endpoints.js

@@ -28,6 +28,7 @@ function update(params) {
       `Failed to configure platform '${platform}': no endpoint defined`
     );
   }
+  config.endpoint = endpoint.replace(/[^/]$/, '$&/');
   let { host } = config;
   // extract host from endpoint
   host = host || (endpoint && URL.parse(endpoint).host);

test/platform/vsts/__snapshots__/vsts-got-wrapper.spec.js.snap

@@ -25,12 +25,12 @@ WebApi {
       "userAgent": "vsts-node-api",
     },
   },
-  "serverUrl": "myEndpoint",
+  "serverUrl": "myEndpoint/",
   "vsoClient": VsoClient {
     "_initializationPromise": Promise {},
     "_locationsByAreaPromises": Object {},
-    "basePath": "myEndpoint",
-    "baseUrl": "myEndpoint",
+    "basePath": "myEndpoint/",
+    "baseUrl": "myEndpoint/",
     "restClient": RestClient {
       "client": HttpClient {
         "_certConfig": undefined,

test/util/__snapshots__/endpoints.spec.js.snap

@@ -2,7 +2,7 @@
 
 exports[`util/endpoints find() allows overrides 1`] = `
 Object {
-  "endpoint": "endpoint",
+  "endpoint": "endpoint/",
   "name": "GitHub",
   "other": "data",
   "platform": "github",