Update automated_testing.md with new go version

automated_testing.md

@@ -308,7 +308,7 @@ output "public_dns" {
 Install Go on your training workstation
 
 ```bash
- wget -c https://dl.google.com/go/go1.14.2.linux-amd64.tar.gz -O - | sudo tar -xz -C /usr/local
+wget -c https://dl.google.com/go/go1.18.1.linux-amd64.tar.gz -O - | tar -xz -C /usr/local
 export PATH=$PATH:/usr/local/go/bin
 ```
 
@@ -439,4 +439,4 @@ The final step of our test is to undeploy everything at the end. Terratest allow
 	defer terraform.Destroy(t, terraformOptions)
 ```
 
-In Go, defer is a statement that will tell your test to run this command last no matter what. Even if the test fails, or errors out somewhere in the code during runtime, this `terraform.Destroy` line will always run to ensure your test infrastructure doesn't become unmanaged by Terraform and difficult to find.
+In Go, defer is a statement that will tell your test to run this command last no matter what. Even if the test fails, or errors out somewhere in the code during runtime, this `terraform.Destroy` line will always run to ensure your test infrastructure doesn't become unmanaged by Terraform and difficult to find.