Allow custom API endpoint

README.md

@@ -38,6 +38,7 @@ You can establish values for a number of SparkPost settings in the initializer.
 
 ```ruby
 SparkPostRails.configure do |c|
+  c.api_endpoint = "https://api.eu.sparkpost.com/api/v1/transmissions" # default: "https://api.sparkpost.com/api/v1/transmissions"
   c.sandbox = true                                # default: false
   c.track_opens = true                            # default: false
   c.track_clicks = true                           # default: false

lib/sparkpost_rails.rb

@@ -18,6 +18,7 @@ def self.configure
   end
 
   class Configuration
+    attr_accessor :api_endpoint
     attr_accessor :api_key
     attr_accessor :sandbox
 
@@ -45,6 +46,8 @@ def set_defaults
         @api_key = ""
       end
 
+      @api_endpoint = "https://api.sparkpost.com/api/v1/transmissions"
+
       @sandbox = false
 
       @track_opens = false

lib/sparkpost_rails/delivery_method.rb

@@ -377,7 +377,7 @@ def prepare_api_headers_from sparkpost_data
     end
 
     def post_to_api
-      url = "https://api.sparkpost.com/api/v1/transmissions"
+      url = SparkPostRails.configuration.api_endpoint
 
       uri = URI.parse(url)
       http = Net::HTTP.new(uri.host, uri.port)