adding CFLAGS to work around deprecated-declarations.

Versions:
* libglib2.0-dev 2.36.3-2
* gcc 4:4.8.1-1

Error: # github.com/ziutek/glib
type.go:19:1: error: 'g_type_init' is deprecated (declared at
/usr/include/glib-2.0/gobject/gtype.h:669)
[-Werror=deprecated-declarations]
 )
  ^
  cc1: all warnings being treated as errors