Add required package for travis and Dockerfile

.travis.yml

@@ -12,7 +12,7 @@ addons:
 before_install:
   - sudo apt-get update -qq
   - sudo apt-get install -qq libcairo2-dev libjpeg8-dev libpango1.0-dev libgif-dev build-essential g++
-  - sudo apt-get install -qq xvfb
+  - sudo apt-get install -qq xvfb libgles2-mesa-dev libxxf86vm-dev
 install:
   - npm install
   - wget -O test_data.zip https://github.com/klokantech/tileserver-gl/releases/download/v1.3.0/test_data.zip

Dockerfile

@@ -9,7 +9,9 @@ RUN apt-get -qq update \
     build-essential \
     python \
     libcairo2-dev \
+    libgles2-mesa-dev \
     libprotobuf-dev \
+    libxxf86vm-dev \
     xvfb \
 && echo "deb https://deb.nodesource.com/node_6.x jessie main" >> /etc/apt/sources.list.d/nodejs.list \
 && echo "deb-src https://deb.nodesource.com/node_6.x jessie main" >> /etc/apt/sources.list.d/nodejs.list \