Merge pull request #2 from SharkPunch/krane-2.1.6

Bump Krane to 2.1.6, kubectl to 1.20.2 and ejson to 1.2.2

Dockerfile

@@ -1,11 +1,13 @@
 FROM ruby:3.0.0
 
-ENV KUBECTL_VERSION=v1.18.2
-ENV EJSON_VERSION=1.2.1
-ENV KRANE_VERSION=1.1.3
+ENV KUBECTL_VERSION=v1.20.2
+ENV EJSON_VERSION=1.2.2
+ENV KRANE_VERSION=2.1.6
 
 RUN curl -L https://storage.googleapis.com/kubernetes-release/release/${KUBECTL_VERSION}/bin/linux/amd64/kubectl -o /usr/local/bin/kubectl \
     && chmod +x /usr/local/bin/kubectl
 
-RUN gem install ejson -v $EJSON_VERSION
+RUN curl -L https://github.com/Shopify/ejson/releases/download/v${EJSON_VERSION}/ejson-${EJSON_VERSION}.gem \
+  -o ejson-${EJSON_VERSION}.gem \
+  && gem install --local ejson-${EJSON_VERSION}.gem
 RUN gem install krane -v $KRANE_VERSION