Add cmocka to Travis CI builds on Ubuntu

.travis.yml

@@ -36,6 +36,7 @@ addons:
         - libudev-dev
         - autopoint
         - faketime
+        - libcmocka-dev
     homebrew:
         packages:
         - libusb

configure.ac

@@ -74,7 +74,7 @@ AM_COND_IF([HAVE_DOXYGEN],
     [AC_MSG_WARN(["Doxygen not found; continuing without doxygen support"])])
 
 # cmocka unit tests, currently only supported on Linux
-AX_PKG_CHECK_MODULES([CMOCKA], [cmocka], [], [have_cmocka=yes], [have_cmocka=no])
+AX_PKG_CHECK_MODULES([CMOCKA], [cmocka >= 1.1], [], [have_cmocka=yes], [have_cmocka=no])
 AM_CONDITIONAL([HAVE_CMOCKA], [test "x$have_cmocka" = xyes])
 AM_COND_IF([HAVE_CMOCKA], [AM_COND_IF([LINUX], [],
     [AC_MSG_WARN(["cmocka found, but cannot build on ${host_os}])])],