Removed mention of node 4 support (#335)

* Remove mention of node 4 support from README

* Remove mention of node 4 support from CONTRIBUTING

* Add mention about node16 testing

Author: localconst

CONTRIBUTING.md

@@ -7,15 +7,15 @@ To build and test you need LTS Node >= 6.12.0 and Npm 5.5.1 (we use lock files).
 For contributions, we recommend using Node 10.15.1 and Npm 6.9.0 in order to minimize friction between package-lock formatting.
 
 ## Build
- 
+
 ```
 $ npm install
 $ npm run build
 ```
 
 ## Test
 
-You should test with node 4.x, 6.x and 8.x LTS.  We recommend using nvm ([linux](https://github.com/creationix/nvm) / [windows](https://github.com/coreybutler/nvm-windows))
+You should test with node 6.x, 8.x and 16.x LTS.  We recommend using nvm ([linux](https://github.com/creationix/nvm) / [windows](https://github.com/coreybutler/nvm-windows))
 
 ```
 npm test

README.md

@@ -71,11 +71,9 @@ or
 set NODE_DEBUG=http
 ```
 
-
-
 ## Node support
 
-The typed-rest-client is built using the latest LTS version of Node 8. We also support the latest LTS for Node 4 and Node 6.
+The typed-rest-client is built using the latest LTS version of Node 8. We also support the latest LTS for Node 6 and newer.
 
 ## Contributing