Support custom headers

Author: dapi

app/views/grape_swagger_rails/application/index.html.erb

@@ -12,6 +12,7 @@
       apiKey: "<%= GrapeSwaggerRails.apiKey %>",
       dom_id:"swagger-ui-container",
       supportHeaderParams: true,
+      headers: "<%= GrapeSwaggerRails.headers.to_json %>",
       supportedSubmitMethods: ['get', 'post', 'put'],
       onComplete: function(swaggerApi, swaggerUi){
         if(console) {

lib/grape-swagger-rails.rb

@@ -1,10 +1,11 @@
 require "grape-swagger-rails/engine"
 
 module GrapeSwaggerRails
-  mattr_accessor :discoveryUrl, :apiKey
+  mattr_accessor :discoveryUrl, :apiKey, :headers
 
   self.discoveryUrl = '/swagger_doc.json'
   self.apiKey = 'special-key'
+  self.headers = {}
 
 end