Upgrade to GitHub-native Dependabot

.github/dependabot.yml

@@ -0,0 +1,47 @@
+version: 2
+updates:
+- package-ecosystem: cargo
+  directory: "/"
+  schedule:
+    interval: monthly
+    time: "07:00"
+  open-pull-requests-limit: 10
+  ignore:
+  - dependency-name: env_logger
+    versions:
+    - 0.8.3
+  - dependency-name: once_cell
+    versions:
+    - 1.7.0
+  - dependency-name: ahash
+    versions:
+    - 0.7.0
+    - 0.7.2
+  - dependency-name: bstr
+    versions:
+    - 0.2.15
+  - dependency-name: nom
+    versions:
+    - 6.1.0
+    - 6.1.2
+  - dependency-name: thiserror
+    versions:
+    - 1.0.24
+  - dependency-name: serde_json
+    versions:
+    - 1.0.64
+  - dependency-name: syn
+    versions:
+    - 1.0.60
+  - dependency-name: log
+    versions:
+    - 0.4.14
+  - dependency-name: derive_setters
+    versions:
+    - 0.1.5
+  - dependency-name: predicates
+    versions:
+    - 1.0.7
+  - dependency-name: proc-exit
+    versions:
+    - 1.0.2