新增learn-kubernetes（https://github.com/yyong-brs/learn-kubernetes）相关文件

learn/learn-kubernetes-master/kiamol/ch19/docker-images/stress/Dockerfile

@@ -0,0 +1,16 @@
+FROM debian:buster-slim
+
+RUN apt-get update \
+ && apt-get install -y --no-install-recommends \
+    bc \
+    stress \
+ && rm -rf /var/lib/apt/lists/*
+
+ ENV MEMORY_STRESS_MB="50" \
+     MEMORY_STRESS_FACTOR="" \
+     STRESS_HANG="3540" \
+     STRESS_TIMEOUT="3600"
+
+COPY ./stress-memory.sh .
+
+CMD chmod +x ./stress-memory.sh && ./stress-memory.sh