Update Cargo.lock, Bump msrv to 1.42 (#1528)

* Update Cargo.lock

* Bump MSRV to 1.42.

There are a few dependencies that require this version.

Author: ehuss

.github/workflows/main.yml

@@ -31,7 +31,7 @@ jobs:
             rust: stable
           - build: msrv
             os: ubuntu-latest
-            rust: 1.39.0
+            rust: 1.42.0
     steps:
     - uses: actions/checkout@master
     - name: Install Rust