feat: add a generic API request interface

lib/easypost/client.rb

@@ -144,6 +144,22 @@ def unsubscribe_all_response_hooks
     EasyPost::Hooks.unsubscribe_all(:response)
   end
 
+  # Make an API call to the EasyPost API
+  #
+  # This public, generic interface is useful for making arbitrary API calls to the EasyPost API that
+  # are not yet supported by the client library's services. When possible, the service for your use case
+  # should be used instead as it provides a more convenient and higher-level interface depending on the endpoint.
+  #
+  # @param method [Symbol] the HTTP Verb (get, post, put, patch, delete, etc.)
+  # @param endpoint [String] URI path of the resource
+  # @param params [Object] (nil) object to be used as the request parameters
+  # @return [EasyPost::Models::EasyPostObject] EasyPost object parsed from the response body
+  def make_api_call(method, endpoint, params = nil)
+    response = make_request(method, endpoint, params)
+
+    EasyPost::InternalUtilities::Json.convert_json_to_object(response)
+  end
+
   private
 
   def http_config

spec/client_spec.rb

@@ -233,5 +233,14 @@
         expect(EasyPost::Hooks.any_subscribers?(:response)).to eq(false)
       end
     end
+
+    it 'make an API call using the generic make_api_call method', :vcr do
+      client = described_class.new(api_key: ENV['EASYPOST_TEST_API_KEY'])
+
+      response = client.make_api_call(:get, '/addresses', { page_size: 1 })
+
+      expect(response['addresses'].length).to eq(1)
+      expect(response['addresses'][0]['object']).to eq('Address')
+    end
   end
 end