Update Compatibility section in Readme

README.md

@@ -100,21 +100,20 @@ Then you need to initialize Dynamoid config to get it going. Put code similar to
     config.namespace = "dynamoid_app_development" # To namespace tables created by Dynamoid from other tables you might have. Set to nil to avoid namespacing.
     config.endpoint = 'http://localhost:3000' # [Optional]. If provided, it communicates with the DB listening at the endpoint. This is useful for testing with [Amazon Local DB] (http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Tools.DynamoDBLocal.html).
   end
-
 ```
 
-### Ruby  & Rails Compatibility Matrix
+### Ruby & Rails Compatibility
+
+Dynamoid supports Ruby >= 2.3 and Rails >= 4.2.
+
+Its compatibility is tested in following way:
 
-| Ruby / Active Record  | 4.0.x | 4.1.x | 4.2.x | 5.0.x |
+| Ruby / Active Record  | 4.2.x | 5.0.x | 5.1.x | 5.2.x |
 |:---------------------:|:-----:|:-----:|:-----:|:-----:|
-| 2.0.0                 | ✓     | ✓     | ✓     |       |
-| 2.1.x                 | ✓     | ✓     | ✓     |       |
-| 2.2.0-2.2.1           | ✓     | ✓     | ✓     |       |
-| 2.2.2+                | ✓     | ✓     | ✓     | ✓     |
-| 2.3.x                 | ✓     | ✓     | ✓     | ✓     |
-| 2.3.x                 | ✓     | ✓     | ✓     | ✓     |
-| 2.4.x                 |       |       | ✓     | ✓     |
-| jruby-9.X             | ✓     | ✓     | ✓     | ✓     |
+| 2.3.7                 | ✓     | ✓     | ✓     | ✓     |
+| 2.4.4                 | ✓     | ✓     | ✓     | ✓     |
+| 2.5.1                 | ✓     | ✓     | ✓     | ✓     |
+| jruby-10.2.0.0        | ✓     | ✓     | ✓     | ✓     |
 
 ## Setup