fix(ci): MSRV

Author: paolobarbolini

.github/workflows/ci.yml

@@ -63,8 +63,8 @@ jobs:
             rust: beta
           - name: nightly
             rust: nightly
-          - name: MSRV 1.64
-            rust: 1.64
+          - name: MSRV 1.70
+            rust: 1.70
 
     steps:
       - uses: actions/checkout@v2