Adjust build sequence

Author: nerdcha

Dockerfile

@@ -1,21 +1,7 @@
 FROM kaggle/python0:latest
 
     # Install OpenCV-3 with Python support
-RUN apt-get update && \
-    # The apt-get version of imagemagick has gone mad, and wants to remove sysvinit.
-    apt-get -y build-dep imagemagick && \
-    wget http://www.imagemagick.org/download/ImageMagick-6.9.3-0.tar.gz && \
-    tar xzf ImageMagick-6.9.3-0.tar.gz && cd ImageMagick-6.9.3-0 && ./configure && \
-    make && make install && \
-    apt-get -y install libgtk2.0-dev pkg-config libavcodec-dev libavformat-dev libswscale-dev && \
-    apt-get -y install libtbb2 libtbb-dev libjpeg-dev libtiff-dev libjasper-dev && \
-    # apt-get gives you cmake 2.8, which fails to find Py3.4's libraries and headers. The current
-    # version is cmake 3.2, which does.
-    cd /usr/local/src && git clone https://github.com/Kitware/CMake.git && \
-    # --system-curl needed for OpenCV's IPP download, see https://stackoverflow.com/questions/29816529/unsupported-protocol-while-downlod-tar-gz-package/32370027#32370027
-    cd CMake && ./bootstrap --system-curl && make && make install && \
-    cd /usr/local/src && git clone https://github.com/Itseez/opencv.git && \
-    cd /usr/local/src/opencv && \
+RUN cd /usr/local/src/opencv && \
     mkdir build && cd build && \
     cmake -D CMAKE_BUILD_TYPE=RELEASE -D CMAKE_INSTALL_PREFIX=/usr/local -D WITH_TBB=ON -D WITH_FFMPEG=OFF -D WITH_V4L=ON -D WITH_QT=OFF -D WITH_OPENGL=ON -D PYTHON3_LIBRARY=/opt/conda/lib/libpython3.4m.so -D PYTHON3_INCLUDE_DIR=/opt/conda/include/python3.4m/ -D PYTHON_LIBRARY=/opt/conda/lib/libpython3.4m.so -D PYTHON_INCLUDE_DIR=/opt/conda/include/python3.4m/ .. && \
     make -j $(nproc) && make install && \