Merge pull request #20 from ryanholte/master

Adds got agent option

Author: OndraFiedler

lib/api-client.js

@@ -46,7 +46,8 @@ class ApiClient {
         headers: {'Accept': 'application/json',
                   'Content-Type': 'application/json',
                   'User-Agent': 'recombee-node-api-client/4.0.0'},
-        timeout: request.timeout
+        timeout: request.timeout,
+        agent: this.options.agent
     };
 
     if (Object.entries(request.bodyParameters()).length > 0)