README.md in dev_orbit-0.0.5 vs README.md in dev_orbit-0.0.6

@@ -17,9 +17,18 @@
 
 ### Instantiation of the Client
 
 To instantiate a DevOrbit client, you can either pass along your credentials for DEV and Orbit directly to the instantiation or retain them in your environment variables.
 
+The following are the expected environment variables:
+
+```ruby
+ORBIT_API_KEY
+ORBIT_WORKSPACE_ID
+DEV_API_KEY
+DEV_USERNAME
+```
+
 With the credentials as environment variables:
 
 ```ruby
 client = DevOrbit::Client.new
 ```