Add support for fullstory relay options

Author: Blackburn29

.gitignore

@@ -1,3 +1,4 @@
+.idea/
 bin/
 node_modules/
 coverage/

integrations/fullstory/lib/index.js

@@ -21,9 +21,11 @@ var FullStory = (module.exports = integration('FullStory')
   .option('trackNamedPages', false)
   .option('trackCategorizedPages', false)
   .option('trackPagesWithEvents', true)
+  .option('script', 'edge.fullstory.com/s/fs.js')
+  .option('host', 'fullstory.com')
   .option('isOuterScript', false)
   .tag(
-    '<script async src="https://edge.fullstory.com/s/fs.js" crossorigin="anonymous"></script>'
+    '<script async src="https://{{script}}" crossorigin="anonymous"></script>'
   ));
 
 /**
@@ -39,8 +41,8 @@ var apiSource = 'segment';
 FullStory.prototype.initialize = function() {
   window._fs_is_outer_script = this.options.isOuterScript;
   window._fs_debug = this.options.debug;
-  window._fs_host = 'fullstory.com';
-  window._fs_script = 'edge.fullstory.com/s/fs.js';
+  window._fs_host = this.options.host;
+  window._fs_script = this.options.script;
   window._fs_org = this.options.org;
   window._fs_namespace = 'FS';