Upgrade to GitHub-native Dependabot

.github/dependabot.yml

@@ -0,0 +1,37 @@
+version: 2
+updates:
+- package-ecosystem: gomod
+  directory: "/"
+  schedule:
+    interval: weekly
+    time: "11:00"
+  open-pull-requests-limit: 10
+  target-branch: dependency-upgrades
+  labels:
+  - topic/dependencies
+  ignore:
+  - dependency-name: github.com/multiformats/go-multiaddr-dns
+    versions:
+    - 0.3.0
+  - dependency-name: github.com/ipfs/go-ds-crdt
+    versions:
+    - 0.1.20
+  - dependency-name: github.com/hsanjuan/ipfs-lite
+    versions:
+    - 1.1.19
+  - dependency-name: github.com/golang/protobuf
+    versions:
+    - 1.5.1
+  - dependency-name: github.com/libp2p/go-libp2p-secio
+    versions:
+    - 0.2.3
+  - dependency-name: github.com/ipfs/go-ipfs-pinner
+    versions:
+    - 0.1.0
+    - 0.1.1
+  - dependency-name: github.com/multiformats/go-multicodec
+    versions:
+    - 0.2.0
+  - dependency-name: github.com/ugorji/go/codec
+    versions:
+    - 1.2.3