Moving Andy Reitz, David Turner and Travis Crawford to Committer Emer…

…itus status

Honoring those committers who have been active in the past but now have retired from Pants life.

Testing Done:
CI green at https://travis-ci.org/pantsbuild/pants/builds/147047048

Bugs closed: 3721

Reviewed at https://rbcommons.com/s/twitter/r/4118/

COMMITTERS.md

@@ -1,12 +1,10 @@
 Active Committers
 =================
 
-Andy Reitz
 Nick Howard
 Benjy Weinberger
 Chris Heisterkamp
 Matt Olsen
-David Turner
 Eric Ayers
 Fedor Korotkov
 Garrett Malmquist
@@ -16,13 +14,15 @@ Kris Wilson
 Larry Hosken
 Mateo Rodriguez
 Patrick Lawson
-Peiyu Want
+Peiyu Wang
 Stu Hood
-Tejal
-Travis Crawford
+Tejal Desai
 Yi Cheng
 
 Emeritus
 ========
 
+Andy Reitz
 David Taylor
+David Turner
+Travis Crawford