fix main branch name (#22)

Signed-off-by: Tihomir Surdilovic <tihomir@temporal.io>

Author: tsurdilo

.github/workflows/Go-SDK-PR-Check.yaml

@@ -21,7 +21,7 @@ on:
       - "LICENSE"
       - "Makefile"
     branches:
-      - master
+      - main
 env:
   GO_VERSION: 1.14
   GOLANGLINT_CI_VERSION: v1.33.0

README.md

@@ -1,6 +1,6 @@
 # Go SDK for Serverless Workflow
 
-Here you will find all the [specification types](https://github.com/serverlessworkflow/specification/blob/master/schema/workflow.json) defined by our Json Schemas, in Go.
+Here you will find all the [specification types](https://github.com/serverlessworkflow/specification/blob/main/schema/workflow.json) defined by our Json Schemas, in Go.
 
 Current status of features implemented in the SDK is listed in the table below:
 

maintainer_guidelines.md

@@ -16,14 +16,14 @@ Here are a few tips for repository maintainers.
 
 ## Branch Management
 
-The `master` branch is is the bleeding edge. New major versions of the module
+The `main` branch is is the bleeding edge. New major versions of the module
 are cut from this branch and tagged. If you intend to submit a pull request
-you should use `master HEAD` as your starting point.
+you should use `main HEAD` as your starting point.
 
 Each major release will result in a new branch and tag. For example, the
 release of version 1.0.0 of the project results in a `v1.0.0` tag on the
 release commit, and a new branch `release-1.y.z` for subsequent minor and patch
 level releases of that major version if necessary. However, development will continue
-apace on `master` for the next major version - e.g. 2.0.0. Version branches
+apace on `main` for the next major version - e.g. 2.0.0. Version branches
 are only created for each major version. Minor and patch level releases
 are simply tagged.

parser/testdata/applicationrequest.url.json

@@ -4,8 +4,8 @@
     "version": "1.0",
     "name": "Applicant Request Decision Workflow",
     "description": "Determine if applicant request is valid",
-    "functions": "https://raw.githubusercontent.com/serverlessworkflow/sdk-java/master/api/src/test/resources/features/applicantrequestfunctions.json",
-    "retries" : "https://raw.githubusercontent.com/serverlessworkflow/sdk-java/master/api/src/test/resources/features/applicantrequestretries.json",
+    "functions": "https://raw.githubusercontent.com/serverlessworkflow/sdk-java/main/api/src/test/resources/features/applicantrequestfunctions.json",
+    "retries" : "https://raw.githubusercontent.com/serverlessworkflow/sdk-java/main/api/src/test/resources/features/applicantrequestretries.json",
     "states":[
       {
         "name":"CheckApplication",