Add sdl, gtest, and cppcheck

Dockerfile

@@ -1,10 +1,13 @@
 FROM debian:buster-slim
 ENV DEBIAN_FRONTEND noninteractive
 
+# Timezone
 ENV TZ=America/New_York
 RUN ln -snf /usr/share/zoneinfo/$TZ /etc/localtime && echo $TZ > /etc/timezone
 
-RUN apt-get -y update && apt-get -y install \
+# Packages
+RUN apt-get -y update
+RUN apt-get -y install \
 	bc \
 	build-essential \
 	bzip2 \
@@ -23,18 +26,28 @@ RUN apt-get -y update && apt-get -y install \
 	unzip \
 	wget \
 	zip \
-	locales\
-  && rm -rf /var/lib/apt/lists/*
+	locales \
+	libsdl1.2-dev \
+	libsdl-image1.2-dev \
+	libsdl-ttf2.0-dev \
+	libsdl-gfx1.2-dev \
+	libgtest-dev \
+	cppcheck
 
+RUN rm -rf /var/lib/apt/lists/*
+
+# Locale
 RUN sed -i '/en_US.UTF-8/s/^# //g' /etc/locale.gen && \
-    locale-gen
+	locale-gen
 ENV LANG en_US.UTF-8  
 ENV LANGUAGE en_US:en  
 ENV LC_ALL en_US.UTF-8     
 
+# Workspace
 RUN mkdir -p /root/workspace
 WORKDIR /root
 
+# Setup
 COPY support .
 RUN ./setup-toolchain.sh
 RUN cat setup-env.sh >> .bashrc