chore: use a newer SDL2 package (#30)

Author: raphaelcoeffic

dev/Dockerfile

@@ -35,7 +35,6 @@ RUN apt-get update && \
         build-essential \
         dumb-init \
         libfox-1.6-dev python3-clang-10 \
-        libsdl2-dev \
         cmake \
         kitware-archive-keyring \
         git \
@@ -62,6 +61,9 @@ RUN apt-get update && \
                ru_RU.UTF-8 sv_SE.UTF-8 zh_TW.UTF-8 uk_UA.UTF-8 && \
     # Install global npm package
     npm i lv_font_conv -g && \
+    # Set up Rob Savoury's PPA for newer SDL2
+    add-apt-repository ppa:savoury1/multimedia --yes && \
+    apt-get install --yes --no-install-recommends libsdl2-dev  && \
     # Clean up
     apt-get clean && rm -rf /var/lib/apt/lists/*