change PMC Chair to slawrence

Author: mbeckerle

site/_data/contributors.yml

@@ -23,7 +23,7 @@
   last: Beckerle
   apacheId: mbeckerle
   githubId: mbeckerle
-  role: PMC (Chair)
+  role: PMC
 
 - first: Ryan
   last: Cover
@@ -41,7 +41,7 @@
   last: Lawrence
   apacheId: slawrence
   githubId: stevedlawrence
-  role: PMC
+  role: PMC (Chair)
 
 - first: Brandon
   last: Sloane