Update Qt to 5.9 on Travis/Linux testing
Update Qt to 5.9 on Travis/Linux testing

The Windows builds on Appveyor use 5.9; the macOS builds on Travis use
the latest from Homebrew, which is currently 5.10.

Signed-off-by: Thiago Macieira <0ed1648d92ca0373297a182b1dba1b974ad10d88@intel.com>

thiagomacieira/tinycbor,01org/tinycbor,intel/tinycbor,intel/tinycbor,01org/tinycbor,01org/tinycbor,intel/tinycbor,thiagomacieira/tinycbor,thiagomacieira/tinycbor,thiagomacieira/tinycbor,intel/tinycbor