Update README

Author: Maurizio Turatti

README.md

@@ -26,7 +26,29 @@ Included packages from base image:
 - [aws-cli](https://github.com/aws/aws-cli).
 - [ecs-cli](https://github.com/aws/amazon-ecs-cli)
 
+## Check the installed tools
+
+```bash
+docker run -it --rm --entrypoint="./startup.sh" softinstigate/serverless
+
+=================================================
+Apache Maven 3.6.3 (cecedd343002696d0abb50b32b541b8a6ba2883f)
+Maven home: /usr/share/maven
+Java version: 11.0.9, vendor: Oracle Corporation, runtime: /usr/local/openjdk-11
+Default locale: en, platform encoding: UTF-8
+OS name: "linux", version: "4.19.76-linuxkit", arch: "amd64", family: "unix"
+aws-cli/2.0.59 Python/3.7.3 Linux/4.19.76-linuxkit exe/x86_64.debian.10
+ecs-cli version 1.20.0 (7547c45)
+node v12.19.0
+yarn 1.22.5
+serverless Framework Core: 2.8.0
+Plugin: 4.1.1
+SDK: 2.3.2
+Components: 3.2.7
+=================================================
+```
+
 ## Additional packages ##
 
-- Nodejs 10.x
-- Serverless cli
+- Nodejs 12 LTS
+- Serverless cli 2.x