[COMMITTERS] Update committers list

Thanks for all your contributions!

Signed-off-by: Michael Munday <[email protected]>

COMMITTERS

@@ -6,10 +6,8 @@ Committers are listed alphabetically by surname in the format:
 * Full Name (GitHubID)
 
 Committer list:
-* Mark Branstad (mwbranstad)
 * Harry Callahan (hcallahan-lowrisc)
 * Greg Chadwick (GregAC)
-* Cindy Chen (cindychip)
 * Miles Dai (milesdai)
 * Jon Flatley (jon-flatley)
 * Chris Frantz (cfrantz)
@@ -20,7 +18,6 @@ Committer list:
 * Marno van der Maas (marnovandermaas)
 * Rasmus Madsen (rasmus-madsen)
 * Guillermo Maturana (matutem)
-* Dan McArdle (dmcardle)
 * Hugo McNally (HU90m)
 * Felix Miller (felixmiller)
 * Michael Munday (mundaym)
@@ -33,7 +30,6 @@ Committer list:
 * Eitan Shapira (eshapira)
 * Rupert Swarbrick (rswarbrick)
 * Timothy Trippel (timothytrippel)
-* Alphan Ulusoy (alphan)
 * Pirmin Vogel (vogelpi)
 * James Wainwright (jwnrt)
 * Alex Williams (a-will)