glib-networking: add ptest

glib-networking: add ptest

Results:
$ ./run-ptest
Running test: glib-networking/connection-gnutls.test
[snip]
PASS: glib-networking/connection-gnutls.test
Running test: glib-networking/file-database-gnutls.test
[snip]
PASS: glib-networking/file-database-gnutls.test
Running test: glib-networking/certificate-gnutls.test
[snip]
PASS: glib-networking/certificate-gnutls.test
SUMMARY: total=3; passed=3; skipped=0; failed=0; user=0.2s; system=0.0s; maxrss=12896

Signed-off-by: Yi Zhao <yi.zhao@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>