rm abis subdir: moved to e1-fake-trau repository The present code repository is meant to contain code for talking to a TRAU DUT, hence the name ice1-trau-tester. The different and separate function of talking to an E1 BTS (Abis instead of Ater, and in the opposite role) was never in scope for this project, but that code got added here in a haste when the InSite BTS arrived while the TRAU bring-up was still blocked. Now that we have our Nokia TCSM2 system working and are doing TRAU experiments, let's keep the code clean.