How to upgrade imagemagic on ubuntu 14.04?

Question

Currently, ImageMagick 6.7.7-10 installed on my Ubuntu 14.04 LTS

# convert -version
Version: ImageMagick 6.7.7-10 2017-07-31 Q16 http://www.imagemagick.org
Copyright: Copyright (C) 1999-2012 ImageMagick Studio LLC
Features: OpenMP

I attempt to upgrade it to ImageMagick-7.0.6-5 follow below steps:

apt-get install build-essential checkinstall && apt-get build-dep imagemagick -y
wget http://www.imagemagick.org/download/ImageMagick.tar.gz
tar xzvf ImageMagick.tar.gz
ls
cd  ImageMagick-7.0.6-5/
./configure
make clean
make
checkinstall
ldconfig /usr/local/lib

But it doesn't work, the installed Image Magick is still ImageMagick 6.7.7-10:

# convert -version
Version: ImageMagick 6.7.7-10 2017-07-31 Q16 http://www.imagemagick.org
Copyright: Copyright (C) 1999-2012 ImageMagick Studio LLC
Features: OpenMP

The output of type -a convert:

convert is /usr/bin/convert

Please help me to upgrade ImageMagic!