Need to add "swig" to installed packages

[TheBankster]

Attempt to build "sharedlib" fails with "make: swig: No such file or directory"
The solution is to add the following line to the list of packages to be installed in install.md:

sudo apt-get install swig

[TheBankster]

Specifically, I'm referring to the error you get if you try to build the sample_app_python:

~/certifier/sample_apps$ ./run_example.sh simple_app_python setup

With the addition of the step I am suggesting, the error goes away.