Fix various MAINTAINERS format inconsistencies

Docker-DCO-1.1-Signed-off-by: Andrew Page <admwiggin@gmail.com> (github: tianon)

contrib/zfs/MAINTAINERS

@@ -1 +1 @@
-Gurjeet Singh <gurjeet@singh.im> (gurjeet.singh.im)
+Gurjeet Singh <gurjeet@singh.im> (@gurjeet)

engine/MAINTAINERS

@@ -1 +1 @@
-Solomon Hykes <solomon@docker.com>
+Solomon Hykes <solomon@docker.com> (@shykes)

integration/MAINTAINERS

@@ -1,4 +1,4 @@
-Solomon Hykes <s@docker.com>
+Solomon Hykes <s@docker.com> (@shykes)
 # WE ARE LOOKING FOR VOLUNTEERS TO HELP CLEAN THIS UP.
 # TO VOLUNTEER PLEASE OPEN A PULL REQUEST ADDING YOURSELF TO THIS FILE.
 # WE WILL HELP YOU GET STARTED. THANKS!

pkg/beam/MAINTAINERS

@@ -1 +1 @@
-Solomon Hykes <solomon@docker.com>
+Solomon Hykes <solomon@docker.com> (@shykes)

pkg/dockerscript/MAINTAINERS

@@ -1 +1 @@
-Solomon Hykes <solomon@docker.com>
+Solomon Hykes <solomon@docker.com> (@shykes)

pkg/signal/MAINTAINERS

@@ -1,2 +1 @@
 Guillaume J. Charmes <guillaume@docker.com> (@creack)
-

server/MAINTAINERS

@@ -1 +1 @@
-Solomon Hykes <solomon@docker.com>
+Solomon Hykes <solomon@docker.com> (@shykes)