[NUCLEO_F4x1RE] export to GCC_ARM

NUCLEO_401RE and NUCLEO_411RE can be exported to GCC_ARM
[NUCLEO_F4x1RE] added to build.travis.py
[DISCO_407VG] added to build_travis.py
Merge pull request #492 from ohagendorf/develop

[NUCLEO_F4x1RE] export to GCC_ARM