Merge pull request #353 from klynton/master

Finally fixes the install of pltraining-classroom.
end is now required
Merge pull request #354 from binford2k/fix/add_kickstart_end

end is now required
Add pe_gem dependency. Bump version.
Merge pull request #356 from casharma/dep/pe_gem

Add pe_gem dependency. Bump version.
Update to PE 3.3.2

Note that the build & boot process inherently patches shellshock.
Merge pull request #357 from binford2k/lms/update_to_332

Update to PE 3.3.2
Prevent students from breaking the master

Fixes #TRAINVM-140
Merge pull request #358 from binford2k/ticket/TRAINVM-140/keep_students_off_master

Prevent students from breaking the master