added Kevin Stiehl as contributor

Author: kr1sp1n

package.json

@@ -68,6 +68,7 @@
     "Jonathan Bastnagel (https://github.com/inkadnb)",
     "Julian Amelung (https://github.com/julianbei)",
     "Karthik Kumar Viswanathan (https://github.com/guilt)",
+    "Kevin Stiehl (https://github.com/kstiehl)",
     "Konstantin Matsiushonak (https://github.com/kakoc)",
     "Mario Pareja (https://github.com/mpareja)",
     "Mark Frost (https://github.com/frostmar)",