Update Dockerfile

Added cmake

Dockerfile

@@ -5,7 +5,7 @@ EXPOSE 3000
 
 USER root
 RUN curl --silent --location https://deb.nodesource.com/setup_6.x | bash -
-RUN apt-get install -y nodejs python-gdal libboost-dev libboost-program-options-dev git
+RUN apt-get install -y nodejs python-gdal libboost-dev libboost-program-options-dev git cmake
 RUN npm install -g nodemon
 
 # Build LASzip and PotreeConverter