Update rust toolchain to 1.46 for CI.

.github/workflows/book.yml

@@ -12,6 +12,10 @@ jobs:
     name: Deploy book on gh-pages
     runs-on: ubuntu-latest
     steps:
+      - uses: actions-rs/toolchain@v1
+        with:
+          toolchain: 1.46
+          override: true
       - name: Checkout
         uses: actions/checkout@v2
       - name: Install mdBook

.github/workflows/ci.yml

@@ -13,6 +13,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v1
+      - uses: actions-rs/toolchain@v1
+        with:
+          toolchain: 1.46
+          override: true
       - name: Check format
         run: cargo fmt --all -- --check
       - name: Check with clippy

.github/workflows/code-coverage.yml

@@ -12,7 +12,7 @@ jobs:
       - uses: actions/checkout@v1
       - uses: actions-rs/toolchain@v1
         with:
-          toolchain: stable
+          toolchain: 1.46
           override: true
       - name: Install libsqlite3-dev
         run: |

.github/workflows/release.yml

@@ -37,6 +37,10 @@ jobs:
 #            registryName: async-graphql-lambda
 #            path: async-graphql-lambda
     steps:
+      - uses: actions-rs/toolchain@v1
+        with:
+          toolchain: 1.46
+          override: true
       - name: Checkout
         uses: actions/checkout@v2
       - name: get version

README.md

@@ -30,7 +30,7 @@
 * [Docs](https://docs.rs/async-graphql)
 * [GitHub repository](https://github.com/async-graphql/async-graphql)
 * [Cargo package](https://crates.io/crates/async-graphql)
-* Minimum supported Rust version: 1.43 or later
+* Minimum supported Rust version: 1.46 or later
 
 ## Safety