adding opencv 3.x to build?

[tyler]

Couple references:
https://gist.github.com/joseph-zhong/372a47bb618111dcd2c81008d00357b2
https://github.com/aeddi/aws-lambda-python-opencv/blob/master/build.sh

[tyler]

Just FYI if this helps anyone, added this step after the do_pip and works (although to note adds ~20mb to zip)

do_source_install () {
    mkdir $VIRTUAL_ENV/src && cd $VIRTUAL_ENV/src && \
    wget -O opencv-3.1.0.zip https://github.com/Itseez/opencv/archive/3.1.0.zip && \
    unzip opencv-3.1.0.zip && \
    rm opencv-3.1.0.zip && \
    mkdir ./opencv-3.1.0/build && \
    cd ./opencv-3.1.0/build && \
    cmake -Wno-dev \
      -D CMAKE_BUILD_TYPE=RELEASE \
      -D BUILD_opencv_python2=ON \
      -D BUILD_SHARED_LIBS=OFF \
      -D WITH_FFMPEG=OFF \
      -D BUILD_EXAMPLES=OFF	\
      -D BUILD_EXAMPLES=OFF	\
      .. && \
    make -j7

    # opencv 3.1 static libs
    mkdir $VIRTUAL_ENV/lib64/python2.7/site-packages/cv2
    cp $VIRTUAL_ENV/src/opencv-3.1.0/build/lib/cv2.so $VIRTUAL_ENV/lib64/python2.7/site-packages/cv2/__init__.so
    touch $VIRTUAL_ENV/lib64/python2.7/site-packages/cv2/__init__.py

}