Given that README.scrapyard shows scrapping of netta boards:

netta2           powerpc     mpc8xx         c51c1c9a    2014-07-07
netta            powerpc     mpc8xx         c51c1c9a    2014-07-07

delete netta example from POST tests.

Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>