[Feature:Autograding] add scheme autograding container (#73)

Add a racket scheme docker container for autograding.

Co-authored-by: Barb Cutler <Barb Cutler>

Author: bmcutler

dockerfiles/scheme/8.18/Dockerfile

@@ -0,0 +1,10 @@
+FROM ubuntu:22.04
+
+# Install necessary packages for Scheme
+RUN apt-get update \
+    && apt-get -y install racket --no-install-recommends \
+    && rm -rf /var/lib/apt/lists/*
+
+WORKDIR /usr/src/app
+
+CMD ["/bin/bash"]

dockerfiles/scheme/metadata.json

@@ -0,0 +1,4 @@
+{
+    "latest" : "8.18"
+    "pushLatest": true
+}