Rename master branch to main #167 (#250)

Author: arey

.github/workflows/maven-build.yml

@@ -5,9 +5,9 @@ name: Java CI with Maven
 
 on:
   push:
-    branches: [ master ]
+    branches: [ main ]
   pull_request:
-    branches: [ master ]
+    branches: [ main ]
 
 jobs:
   build:

README.md

@@ -16,7 +16,7 @@ If everything goes well, you can access the following services at given location
 * Config Server - http://localhost:8888
 * AngularJS frontend (API Gateway) - http://localhost:8080
 * Customers, Vets and Visits Services - random port, check Eureka Dashboard 
-* Tracing Server (Zipkin) - http://localhost:9411/zipkin/ (we use [openzipkin](https://github.com/openzipkin/zipkin/tree/master/zipkin-server))
+* Tracing Server (Zipkin) - http://localhost:9411/zipkin/ (we use [openzipkin](https://github.com/openzipkin/zipkin/tree/main/zipkin-server))
 * Admin Server (Spring Boot Admin) - http://localhost:9090
 * Grafana Dashboards - http://localhost:3000
 * Prometheus - http://localhost:9091
@@ -33,13 +33,13 @@ Alternatively you can also build all the images on Podman, which requires Podman
 Once images are ready, you can start them with a single command
 `docker-compose up` or `podman-compose up`. 
 
-Containers startup order is coordinated with the `service_healthy` condition of the Docker Compose [depends-on](https://github.com/compose-spec/compose-spec/blob/master/spec.md#depends_on) expression 
-and the [healthcheck](https://github.com/compose-spec/compose-spec/blob/master/spec.md#healthcheck) of the service containers. 
+Containers startup order is coordinated with the `service_healthy` condition of the Docker Compose [depends-on](https://github.com/compose-spec/compose-spec/blob/main/spec.md#depends_on) expression 
+and the [healthcheck](https://github.com/compose-spec/compose-spec/blob/main/spec.md#healthcheck) of the service containers. 
 After starting services, it takes a while for API Gateway to be in sync with service registry,
 so don't be scared of initial Spring Cloud Gateway timeouts. You can track services availability using Eureka dashboard
 available by default at http://localhost:8761.
 
-The `master` branch uses an Eclipse Temurin with Java 17 as Docker base image.
+The `main` branch uses an Eclipse Temurin with Java 17 as Docker base image.
 
 *NOTE: Under MacOSX or Windows, make sure that the Docker VM has enough memory to run the microservices. The default settings
 are usually not enough and make the `docker-compose up` painfully slow.*