Add GH action to publish proto files to BSR

GH Action includes:
- check for lint errors
- check for backward compatibility breaking changes

Migrated buf config files from v1beta1 to v1 using command:
'buf config migrate-v1beta1'
(https://docs.buf.build/configuration/v1beta1-migration-guide)

.github/workflows/proto-buf-publisher.yml

@@ -0,0 +1,33 @@
+name: Proto Buf Publishing - Action
+# Protobuf runs buf (https://buf.build/) push updated proto files to https://buf.build/cosmwasm/wasmd
+# This workflow is only run when a .proto file has been changed
+on:
+  push:
+    branches:
+      - master
+    paths:
+      - 'proto/**'
+
+jobs:
+  push:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: bufbuild/buf-setup-action@v0.7.0
+
+      # lint checks
+      - uses: bufbuild/buf-lint-action@v1
+        with:
+          input: 'proto'
+
+      # backward compatibility breaking checks
+      - uses: bufbuild/buf-breaking-action@v1
+        with:
+          input: 'proto'
+          against: 'https://github.com/CosmWasm/wasmd.git#branch=master'
+
+      # publish proto files
+      - uses: bufbuild/buf-push-action@v1
+        with:
+          input: 'proto'
+          buf_token: ${{ secrets.BUF_TOKEN }}

buf.work.yaml

@@ -0,0 +1,9 @@
+# Generated by "buf config migrate-v1beta1". Edit as necessary, and
+# remove this comment when you're finished.
+#
+# This workspace file points to the roots found in your
+# previous "buf.yaml" configuration.
+version: v1
+directories:
+  - proto
+  - third_party/proto

proto/buf.yaml

@@ -0,0 +1,21 @@
+# Generated by "buf config migrate-v1beta1". Edit as necessary, and
+# remove this comment when you're finished.
+#
+# This module represents the "proto" root found in
+# the previous configuration.
+version: v1
+breaking:
+  use:
+    - FILE
+lint:
+  use:
+    - DEFAULT
+    - COMMENTS
+    - FILE_LOWER_SNAKE_CASE
+  except:
+    - UNARY_RPC
+    - COMMENT_FIELD
+    - SERVICE_SUFFIX
+    - PACKAGE_VERSION_SUFFIX
+    - RPC_REQUEST_STANDARD_NAME
+    - PACKAGE_DIRECTORY_MATCH

buf.yaml → third_party/proto/buf.yaml

@@ -1,11 +1,23 @@
-version: v1beta1
-
+# Generated by "buf config migrate-v1beta1". Edit as necessary, and
+# remove this comment when you're finished.
+#
+# This module represents the "third_party/proto" root found in
+# the previous configuration.
+version: v1
 build:
-  roots:
-    - proto
-    - third_party/proto
   excludes:
-    - third_party/proto/google/protobuf
+    - google/protobuf
+breaking:
+  use:
+    - FILE
+  ignore:
+    - confio
+    - cosmos
+    - cosmos_proto
+    - gogoproto
+    - google
+    - ibc
+    - tendermint
 lint:
   use:
     - DEFAULT
@@ -19,21 +31,10 @@ lint:
     - RPC_REQUEST_STANDARD_NAME
     - PACKAGE_DIRECTORY_MATCH
   ignore:
+    - confio
     - cosmos
-    - ibc
-    - tendermint
-    - gogoproto
     - cosmos_proto
+    - gogoproto
     - google
-    - confio
-breaking:
-  use:
-    - FILE
-  ignore:
-    - cosmos
     - ibc
     - tendermint
-    - gogoproto
-    - cosmos_proto
-    - google
-    - confio