Update dependencies to remove some packages (#1057)

* Use new lockfile format

* Update dependencies to remove some packages

cargo update -p tokio-reactor -p tokio-executor -p tokio-timer -p tokio-threadpool -p rand_chacha:0.2.1
    Updating crates.io index
    Removing c2-chacha v0.2.3
    Removing crossbeam-queue v0.1.2
    Removing crossbeam-utils v0.6.6
    Updating rand_chacha v0.2.1 -> v0.2.2
    Updating tokio-executor v0.1.9 -> v0.1.10
    Updating tokio-reactor v0.1.11 -> v0.1.12
    Updating tokio-threadpool v0.1.17 -> v0.1.18
    Updating tokio-timer v0.2.12 -> v0.2.13

* Use actions/checkout v2

Author: JohnTitor

.github/workflows/main.yml

@@ -6,7 +6,7 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v1
+      - uses: actions/checkout@v2
       - name: Formatting
         run: |
           # Install extra rustup components