Always set a user agent

This behavior makes the provider behave the same way as the github
provider.

Author: oliversalzburg

lib/api.js

@@ -79,6 +79,7 @@ function createHooks(config, repo_id, url, callback) {
       url: url,
       push_events: true
     })
+    .set('User-Agent', 'StriderCD (http://stridercd.com)')
     .end(function (err, res) {
       if (err) return callback(err);
       if (res && res.status !== 201) return callback(res.status);
@@ -95,6 +96,7 @@ function deleteHooks(config, repo_id, url, callback) {
   superagent
     .get(endpoint_url)
     .query(qpm)
+    .set('User-Agent', 'StriderCD (http://stridercd.com)')
     .end(function (err, res) {
       var deleted = false;
 
@@ -132,6 +134,7 @@ function addDeployKey(config, repo_id, title, key, callback) {
       title: title,
       key: key
     })
+    .set('User-Agent', 'StriderCD (http://stridercd.com)')
     .end(function (err, res) {
       if (err) return callback(err);
       if (res && res.status !== 201) return callback(res.status);
@@ -148,6 +151,7 @@ function removeDeployKey(config, repo_id, title, callback) {
   superagent
     .get(endpoint_url)
     .query(qpm)
+    .set('User-Agent', 'StriderCD (http://stridercd.com)')
     .end(function (err, res) {
       var deleted = false;