Update soundess dockerfile

Author: FranzBusch

docker/Dockerfile

@@ -1,5 +1,5 @@
-ARG swift_version=5.0
-ARG ubuntu_version=bionic
+ARG swift_version=5.6
+ARG ubuntu_version=focal
 ARG base_image=swift:$swift_version-$ubuntu_version
 FROM $base_image
 # needed to do again after FROM due to docker limitation
@@ -12,23 +12,13 @@ ENV LC_ALL en_US.UTF-8
 ENV LANG en_US.UTF-8
 ENV LANGUAGE en_US.UTF-8
 
-# dependencies
-RUN apt-get update && apt-get install -y wget
-RUN apt-get update && apt-get install -y lsof dnsutils netcat-openbsd net-tools curl jq # used by integration tests
-
-# ruby and jazzy for docs generation
-RUN apt-get update && apt-get install -y ruby ruby-dev libsqlite3-dev build-essential
-# jazzy no longer works on older version of ubuntu as ruby is too old.
-RUN if [ "${ubuntu_version}" = "focal" ] ; then echo "gem: --no-document" > ~/.gemrc ; fi
-RUN if [ "${ubuntu_version}" = "focal" ] ; then gem install jazzy ; fi
-
 # tools
 RUN mkdir -p $HOME/.tools
 RUN echo 'export PATH="$HOME/.tools:$PATH"' >> $HOME/.profile
 
 # swiftformat (until part of the toolchain)
 
-ARG swiftformat_version=0.51.2
+ARG swiftformat_version=0.51.7
 RUN git clone --branch $swiftformat_version --depth 1 https://github.com/nicklockwood/SwiftFormat $HOME/.tools/swift-format
 RUN cd $HOME/.tools/swift-format && swift build -c release
 RUN ln -s $HOME/.tools/swift-format/.build/release/swiftformat $HOME/.tools/swiftformat