.travis.yml: add a new build target with non-core devlibs

The current builds don't include all the features which are
auto-detected and then disabled when the appropriate test packages don't
exist. I've added another target that enables all known additional
packages for increased coverage. I didn't add it to the core package
list to reduce build time.
Signed-off-by: NAlex Bennée <alex.bennee@linaro.org>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NMichael Tokarev <mjt@tls.msk.ru>

.travis.yml

@@ -46,6 +46,10 @@ matrix:
     - env: TARGETS=i386-softmmu,x86_64-softmmu
            EXTRA_CONFIG="--enable-debug --enable-tcg-interpreter"
       compiler: gcc
+    # All the extra -dev packages
+    - env: TARGETS=i386-softmmu,x86_64-softmmu
+           EXTRA_PKGS="libaio-dev libcap-ng-dev libattr1-dev libbrlapi-dev uuid-dev libusb-1.0.0-dev"
+      compiler: gcc
     # Currently configure doesn't force --disable-pie
     - env: TARGETS=i386-softmmu,x86_64-softmmu
            EXTRA_CONFIG="--enable-gprof --enable-gcov --disable-pie"