scripts.avocado: Include scripts directory in PATH

We need to execute avocado in simpletests, thus we need both, libexec
and scripts directories inside PATH.
Signed-off-by: NLukáš Doktor <ldoktor@redhat.com>

scripts/avocado

@@ -20,6 +20,7 @@ import sys
 # simple magic for using scripts within a source tree
 basedir = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
 if os.path.isdir(os.path.join(basedir, 'avocado')):
+    os.environ['PATH'] += ":" + os.path.join(basedir, 'scripts')
     os.environ['PATH'] += ":" + os.path.join(basedir, 'libexec')
     sys.path.append(basedir)