Add Visual Studio Code launch configuration.

.vscode/launch.json

@@ -0,0 +1,29 @@
+{
+  // Use IntelliSense to learn about possible attributes.
+  // Hover to view descriptions of existing attributes.
+  // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+  "version": "0.2.0",
+  "configurations": [
+    {
+      "type": "node",
+      "request": "launch",
+      "name": "Mocha Tests",
+      "program": "${workspaceFolder}/node_modules/mocha/bin/_mocha",
+      "args": [
+        "-u",
+        "tdd",
+        "--timeout",
+        "999999",
+        "--colors",
+        "${workspaceFolder}/test"
+      ],
+      "internalConsoleOptions": "openOnSessionStart"
+    },
+    {
+      "type": "node",
+      "request": "launch",
+      "name": "Launch Program",
+      "program": "${workspaceFolder}/lib/index.js"
+    }
+  ]
+}