fix gitpod (#658)

.gitpod.dockerfile

@@ -0,0 +1,15 @@
+FROM gitpod/workspace-full
+
+RUN sudo apt-get update \
+    && sudo apt-get install -yq --no-install-recommends \
+        libpng16-16 \
+        libpng-dev \
+        pkg-config \
+        autoconf \
+        libtool \
+        build-essential \
+        nasm \
+        libx11-dev \
+        libxkbfile-dev \
+    && sudo rm -rf /var/lib/apt/lists/*
+