Use move -pv on Travis

scripts/install-dependencies.sh

@@ -6,7 +6,7 @@ HERE=$PWD
 
 # Override gcc version to $GCC_VER.
 # Put an appropriate symlink at the front of the path.
-mkdir -v $HOME/bin
+mkdir -pv $HOME/bin
 for g in gcc g++ gcov gcc-ar gcc-nm gcc-ranlib
 do
   test -x $( type -p ${g}-$GCC_VER )