Removed unused phone package

This package was originally an experiment to try to use a phone
for the magnetometer which turned out not to need its own package.
Removed rosserial folder

rosserial folder is a remote folder which should not be tracked by git.
This has been removed as it is not necessary for the operation of the
robot but rather for compiling the arduino code.  If you wish to
compile the arduino code please look at rosserial on the wiki for the
compiler and the source is contained in mst_motors.