Merge pull request #6 from temporalio/tw-upgrade-docker-image

Update devcontainer image version to 1.6

Author: tomwheeler

.devcontainer/devcontainer.json

@@ -1,5 +1,5 @@
 {
-    "image": "temporalio/gitpod-edu:1.4",
+    "image": "temporalio/gitpod-edu:1.6",
     "customizations": {
         "codespaces": {
             "openFiles": [