Add post create command to install gotests package

Author: paulojunior-ufla

.devcontainer/devcontainer.json

@@ -45,7 +45,7 @@
 	// },
 
 	// Use 'postCreateCommand' to run commands after the container is created.
-	// "postCreateCommand": "go version",
+	"postCreateCommand": "go install -v github.com/cweill/gotests/gotests@latest",
 
 	// Uncomment to connect as a non-root user. More info: https://aka.ms/vscode-remote/containers/non-root.
 	"remoteUser": "vscode"