ADD: added new version of protobuf

libs/protobuf/kokoro/linux/dockerfile/test/ruby/Dockerfile

@@ -0,0 +1,44 @@
+FROM debian:stretch
+
+# Install dependencies.  We start with the basic ones require to build protoc
+# and the C++ build
+RUN apt-get update && apt-get install -y \
+  autoconf \
+  autotools-dev \
+  build-essential \
+  bzip2 \
+  ccache \
+  curl \
+  gcc \
+  git \
+  libc6 \
+  libc6-dbg \
+  libc6-dev \
+  libgtest-dev \
+  libtool \
+  make \
+  parallel \
+  time \
+  wget \
+  # Java dependencies
+  maven \
+  openjdk-8-jdk \
+  && apt-get clean
+
+# Install rvm
+RUN gpg --keyserver hkp://keyserver.ubuntu.com --recv-keys \
+    409B6B1796C275462A1703113804BB82D39DC0E3 \
+    7D2BAF1CF37B13E2069D6956105BD0E739499BDB
+RUN \curl -sSL https://raw.githubusercontent.com/rvm/rvm/master/binscripts/rvm-installer | bash -s master
+
+RUN /bin/bash -l -c "rvm install 2.5.1"
+RUN /bin/bash -l -c "rvm install 2.6.0"
+RUN /bin/bash -l -c "rvm install 2.7.0"
+RUN /bin/bash -l -c "rvm install 3.0.0"
+RUN /bin/bash -l -c "rvm install 3.1.0"
+RUN /bin/bash -l -c "rvm install jruby-9.2.20.1"
+RUN /bin/bash -l -c "rvm install jruby-9.3.3.0"
+RUN /bin/bash -l -c "rvm install jruby-9.3.4.0"
+
+RUN /bin/bash -l -c "echo 'gem: --no-ri --no-rdoc' > ~/.gemrc"
+RUN /bin/bash -l -c "echo 'export PATH=/usr/local/rvm/bin:$PATH' >> ~/.bashrc"