Adding tmux to resume session upon failures.

Dockerfile

@@ -24,6 +24,7 @@ RUN rm -f /etc/apt/sources.list.d/*.list && \
     build-essential \
     libsndfile-dev \
     software-properties-common \
+    tmux \
  && rm -rf /var/lib/apt/lists/*
 
 RUN add-apt-repository ppa:flexiondotorg/nvtop && \