gremlin: add "At" alias for "Context"
gremlin: add "At" alias for "Context"

Change-Id: I51777e7901c402b4d69a08923ba7bb66a2322218
Reviewed-on: https://softwarefactory-project.io/r/5442
Reviewed-by: Sylvain Baubeau <b0a7dc08a3f38d713e107103b0a85b0badc14b84@redhat.com>
Tested-by: Sylvain Baubeau <b0a7dc08a3f38d713e107103b0a85b0badc14b84@redhat.com>
Workflow: Sylvain Baubeau <b0a7dc08a3f38d713e107103b0a85b0badc14b84@redhat.com>
Tested-by: Jenkins CI <d95b56ce41a2e1ac4cecdd398defd7414407cc08@softwarefactory-project.io>

lebauce/skydive,redhat-cip/skydive,skydive-project/skydive,skydive-project/skydive,lebauce/skydive,redhat-cip/skydive,safchain/skydive,safchain/skydive,lebauce/skydive,skydive-project/skydive,lebauce/skydive,safchain/skydive,safchain/skydive,skydive-project/skydive,lebauce/skydive,lebauce/skydive,safchain/skydive,lebauce/skydive,lebauce/skydive,skydive-project/skydive,skydive-project/skydive,redhat-cip/skydive,skydive-project/skydive,safchain/skydive,safchain/skydive,safchain/skydive