Added Rails 5 Redshift adapter to docs

README.md

@@ -448,7 +448,7 @@ data_sources:
 
 ### Redshift
 
-Add [activerecord4-redshift-adapter](https://github.com/aamine/activerecord4-redshift-adapter) to your Gemfile and set:
+Add [activerecord4-redshift-adapter](https://github.com/aamine/activerecord4-redshift-adapter) or [activerecord5-redshift-adapter](https://github.com/ConsultingMD/activerecord5-redshift-adapter) to your Gemfile and set:
 
 ```yml
 data_sources: