Updated Bootstrap class.

* updated Bootstrap class with the read_bootstrap_file function,
which reads data from a bootstrap file and loads it into the
current Bootstrap instance.

* added tests for read_bootstrap_file and other functions

* overhauled test naming scheme so that tests can be run usefully
using Nose's regular expressions (-m for match, -e for exclude)

* moved print_header and print_footer out of assoc_memory_tester.py
into utilities.py (which uses to be startup_utils.py) so that they can
be accesed from any class (especially the Bootstrap class).
Added test/config so tests setup properly