Replace buck instruction with bazel from README
Replace buck instruction with bazel from README

Change-Id: I384c9a43c80e6e1e76fa7bbc6c09220ce6058306
(cherry picked from commit 666258f7fc038ced06f6d787267e76f21a5893b0)

opennetworkinglab/onos,gkatsikas/onos,opennetworkinglab/onos,opennetworkinglab/onos,oplinkoms/onos,oplinkoms/onos,kuujo/onos,kuujo/onos,oplinkoms/onos,oplinkoms/onos,gkatsikas/onos,oplinkoms/onos,opennetworkinglab/onos,gkatsikas/onos,opennetworkinglab/onos,gkatsikas/onos,kuujo/onos,kuujo/onos,kuujo/onos,gkatsikas/onos,oplinkoms/onos,gkatsikas/onos,oplinkoms/onos,opennetworkinglab/onos,kuujo/onos,kuujo/onos