Update Dockerfile

Dockerfile

@@ -1,4 +1,4 @@
-FROM rocker/shiny:latest
+FROM rocker/shiny:4.4.0
 
 RUN apt-get update && apt-get install -y \
     libcurl4-openssl-dev \
@@ -30,7 +30,7 @@ COPY app.R /srv/shiny-server/app/app.R
 COPY OA_sheet_for_app.csv /srv/shiny-server/app/OA_sheet_for_app.csv
 COPY all_players_enriched_multiseason.csv /srv/shiny-server/app/all_players_enriched_multiseason.csv
 
-RUN echo '#!/bin/bash\ncd /srv/shiny-server/app && Rscript -e "shiny::runApp(\".\", host=\"0.0.0.0\", port=7860)" 2>&1' > /start.sh \
+RUN printf '#!/bin/bash\ncd /srv/shiny-server/app && Rscript -e "shiny::runApp(\".\", host=\"0.0.0.0\", port=7860)" 2>&1\n' > /start.sh \
     && chmod +x /start.sh
 
 EXPOSE 7860