Update package_sparkfun_index.json

Fixed archiveFileName to version 1.2.0

Author: BrentWilkins

IDE_Board_Manager/package_sparkfun_index.json

@@ -102,7 +102,7 @@
                "version":"1.2.0",
                "category":"Contributed",
                "url":"https://github.com/sparkfun/Arduino_Boards/raw/master/IDE_Board_Manager/sparkfun-samd-1.2.0.tar.bz2",
-               "archiveFileName":"sparkfun-samd-1.1.0.tar.bz2",
+               "archiveFileName":"sparkfun-samd-1.2.0.tar.bz2",
                "checksum":"SHA-256:50E055F311E07BA4D154BF00AA10579648024BEF680BB3EB267401C496F791E6",
                "size":"281932",
                "help":{