FLANN needs explicit installation of libraries.

flann-lib/flann#399

Author: magicwebkraken

install/Dockerfile.flann

@@ -1,6 +1,6 @@
 FROM ann-benchmarks
 
-RUN apt-get update && apt-get install -y cmake
+RUN apt-get update && apt-get install -y cmake pkg-config liblz4-dev
 RUN git clone https://github.com/mariusmuja/flann
 RUN mkdir flann/build
 RUN cd flann/build && cmake ..