Upgrade to GitHub-native Dependabot (graphql-rust#924)

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>
Co-authored-by: Christian Legnitto <[email protected]>

.github/dependabot.yml

@@ -0,0 +1,34 @@
+version: 2
+updates:
+- package-ecosystem: cargo
+  directory: "/"
+  schedule:
+    interval: daily
+  open-pull-requests-limit: 10
+  ignore:
+  - dependency-name: warp
+    versions:
+    - 0.3.0
+    - 0.3.1
+  - dependency-name: tokio
+    versions:
+    - 1.1.0
+    - 1.2.0
+    - 1.3.0
+    - 1.4.0
+  - dependency-name: actix
+    versions:
+    - 0.11.0
+  - dependency-name: actix-rt
+    versions:
+    - 2.0.0
+    - 2.1.0
+  - dependency-name: bytes
+    versions:
+    - 1.0.0
+  - dependency-name: hyper
+    versions:
+    - 0.14.1
+  - dependency-name: rand
+    versions:
+    - 0.8.0