Bump msrv to 1.51

Author: pickfire

.github/workflows/build.yml

@@ -17,7 +17,7 @@ jobs:
           - stable
           - beta
           - nightly
-          - 1.50.0
+          - 1.51.0
         os: [ubuntu-18.04]
         # but only stable on macos/windows (slower platforms)
         include: