Run onos-build-selective-hook with bash to prevent issues on systems with
other default shells
diff --git a/tools/dev/bin/onos-build-selective-hook b/tools/dev/bin/onos-build-selective-hook
index 0b39713..eb4e482 100755
--- a/tools/dev/bin/onos-build-selective-hook
+++ b/tools/dev/bin/onos-build-selective-hook
@@ -1,3 +1,4 @@
+#!/bin/bash
 #------------------------------------------------------------------------------
 # Echoes project-level directory if a Java file within is newer than the
 # target directory.