convert master to main

.github/workflows/ci.yml

@@ -2,9 +2,9 @@ name: CI
 
 on:
   push:
-    branches: [ master ]
+    branches: [ main ]
   pull_request:
-    branches: [ master ]
+    branches: [ main ]
 
 jobs:
   go-pipeline:

.whitesource

@@ -5,4 +5,4 @@
   "issueSettings": {
     "minSeverityLevel": "LOW"
   }
-}
+}

CONTRIBUTING.md

@@ -25,7 +25,7 @@ go test -mod=vendor .
 
 Godo follows [semver](https://www.semver.org) versioning semantics.
 New functionality should be accompanied by increment to the minor
-version number. Any code merged to master is subject to release.
+version number. Any code merged to main is subject to release.
 
 ## Releasing