Update .mailmap

Change-Id: I167f9e4746b8aa814b361e884c3c9a25e95b9d54
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>

.mailmap

@@ -1,3 +1,4 @@
+Mark Ingram <markdingram@gmail.com>          markdingram <markdingram@gmail.com>
 Roberto Tyley <roberto.tyley@guardian.co.uk> roberto <roberto.tyley@guardian.co.uk>
 Saša Živkov <sasa.zivkov@sap.com>            Sasa Zivkov <sasa.zivkov@sap.com>
 Saša Živkov <sasa.zivkov@sap.com>            Saša Živkov <zivkov@gmail.com>