update to latest b-series submodule

tinyfpga · tinyfpga · commit 77b783bbdcd8 · 2017-10-16T23:57:08.000-07:00
diff --git a/b-series b/b-series
@@ -1 +1 @@
-Subproject commit 059f7de3dcbaf530ba3a44a8d03b96ccef447ef0
+Subproject commit 1242674bcef9c62a6220db2675373f0dc30c9b64
