[announce] add this month's contributor list

docs/announce/2015.07.md

@@ -34,7 +34,11 @@ Parrot, the Perl 6 test suite, MoarVM and the specification.
 
 The following people contributed to this release:
 
-tbd
+Jonathan Worthington, Elizabeth Mattijsen, skids, Tobias Leich, Christian
+Bartolomäus, Moritz Lenz, Jonathan Scott Duff, Timo Paulssen, Nick Logan, Larry
+Wall, Carl Mäsak, Will "Coke" Coleda, Steve Mynott, Rob Hoelz, Jimmy Zhuo,
+Stefan Seifert, ShimmerFairy, Jonathan Stowe, Lucas Buchala, Stéphane Payrard,
+Bart Wiegmans, Brent Laabs, Daniel Dehennin, Sue Spence
 
 If you would like to contribute, see <http://rakudo.org/how-to-help>,
 ask on the <perl6-compiler@perl.org> mailing list, or ask on IRC #perl6