Rename our allwpilib (which is now 2020) to not have 2019 in the name

Change-Id: I3c07f85ed32ab8b97db765a9b43f2a6ce7da964a
diff --git a/third_party/BUILD b/third_party/BUILD
index 6bb5f9c..b1a5eea 100644
--- a/third_party/BUILD
+++ b/third_party/BUILD
@@ -10,7 +10,7 @@
     name = "wpilib_hal",
     restricted_to = ["//tools:roborio"],
     visibility = ["//visibility:public"],
-    deps = ["//third_party/allwpilib_2019:hal"],
+    deps = ["//third_party/allwpilib:hal"],
 )
 
 cc_library(