update revisions log

cmaglie · cmaglie · commit a6e36fac9da3 · 2015-12-28T12:32:10.000+01:00
diff --git a/build/shared/revisions.txt b/build/shared/revisions.txt
@@ -7,6 +7,7 @@ ARDUINO 1.6.8
 
 [core]
 * avr: fixed USB_SendControl(...) for buffer with len > 64. Thanks @NicoHood
+* avr: fixed yield() usage inside delay(). Thanks @vbextreme
 
 ARDUINO 1.6.7 - 2015.12.17
 
