Add newest versions of stern and tkn to .devcontainer docker

Remove istioctl

.devcontainer/Dockerfile

@@ -7,20 +7,18 @@ RUN yum -y install bc
 
 # install stern
 RUN cd /usr/local/bin && \
-    wget https://github.com/wercker/stern/releases/download/1.6.0/stern_linux_amd64 && \
+    wget https://github.com/wercker/stern/releases/download/1.11.0/stern_linux_amd64 && \
     mv stern_linux_amd64 stern && chmod 755 stern && \
 # instal hey
     wget https://storage.googleapis.com/hey-release/hey_linux_amd64 && \
-    mv hey_linux_amd64 hey && chmod 755 hey && \
-# install istioctl
-    curl -L https://github.com/istio/istio/releases/download/1.4.0/istioctl-1.4.0-linux.tar.gz | tar -zxvf - -C /usr/local/bin && chmod 755 /usr/local/bin/istioctl
+    mv hey_linux_amd64 hey && chmod 755 hey
 
 # install AWS cli
 RUN curl "https://d1vvhvl2y92vvt.cloudfront.net/awscli-exe-linux-x86_64.zip" -o "awscliv2.zip" && \
     unzip awscliv2.zip && ./aws/install && rm awscliv2.zip && rm -rf ./aws 
     # && ln -s /usr/local/bin/aws2 /usr/local/bin/aws
 
-RUN curl -L https://github.com/tektoncd/cli/releases/download/v0.9.0/tkn_0.9.0_Linux_x86_64.tar.gz | \
+RUN curl -L https://github.com/tektoncd/cli/releases/download/v0.11.0/tkn_0.11.0_Linux_x86_64.tar.gz | \
     tar -xvzf - -C /usr/local/bin/ tkn && chmod 755 /usr/local/bin/tkn