Updates/corrections to travis.yml

1. use release version of Boost 1.54 (we may be able to forget using any binaries at all)
2. moved location where boost will be BOOST_ROOT=/home/travis/boost
3. updated build orders to reflect new boost location

TODO:
1. symlink in AFIO into the new boost location
2. enable install
3. fix directives to build AFIO or to ingnore it