Changes

Introduce ttcn-sccp dockerized setup
Since examples/sccp_demo_user (the binary used to test SCCP) is not 
installed by libosmo-sccp.git during make install, we need to install it 
manually after "make" step, and hence it's only available in 
osmo-stp-master, because in osmo-stp-latest we used packaged files.
Related: OS#4343 Depends: osmo-ttcn3-hacks.git
Ied9fbfb9bd35a99205ca13db033dd9ea03d51238 Change-Id:
I5a7e6ff5f6e5f6e34d6a5ab29bd760a6f9d49c4b