Fix readme links.

Author: OlgaMaciaszek

README.adoc

@@ -5,9 +5,9 @@ Edit the files in the src/main/asciidoc/ directory instead.
 ////
 
 
-image::https://github.com/spring-cloud/spring-cloud-openfeign/workflows/Build/badge.svg?branch=main&style=svg["Build",link="https://github.com/spring-cloud/spring-cloud-openfeign/actions"]
+image::https://github.com/spring-cloud/spring-cloud-openfeign/workflows/Build/badge.svg?branch=3.1.x&style=svg["Build",link="https://github.com/spring-cloud/spring-cloud-openfeign/actions"]
 
-image:https://codecov.io/gh/spring-cloud/spring-cloud-openfeign/branch/main/graph/badge.svg["Codecov", link="https://codecov.io/gh/spring-cloud/spring-cloud-openfeign"]
+image:https://codecov.io/gh/spring-cloud/spring-cloud-openfeign/branch/3.1.x/graph/badge.svg["Codecov", link="https://app.codecov.io/gh/spring-cloud/spring-cloud-openfeign/tree/3.1.x"]
 
 image:https://api.codacy.com/project/badge/Grade/97b04c4e609c4b4f86b415e4437a6484["Codacy code quality", link="https://www.codacy.com/app/Spring-Cloud/spring-cloud-openfeign?utm_source=github.com&utm_medium=referral&utm_content=spring-cloud/spring-cloud-openfeign&utm_campaign=Badge_Grade"]
 

docs/src/main/asciidoc/README.adoc

@@ -1,6 +1,6 @@
-image::https://github.com/spring-cloud/spring-cloud-openfeign/workflows/Build/badge.svg?branch=main&style=svg["Build",link="https://github.com/spring-cloud/spring-cloud-openfeign/actions"]
+image::https://github.com/spring-cloud/spring-cloud-openfeign/workflows/Build/badge.svg?branch=3.1.x&style=svg["Build",link="https://github.com/spring-cloud/spring-cloud-openfeign/actions"]
 
-image:https://codecov.io/gh/spring-cloud/spring-cloud-openfeign/branch/main/graph/badge.svg["Codecov", link="https://codecov.io/gh/spring-cloud/spring-cloud-openfeign"]
+image:https://codecov.io/gh/spring-cloud/spring-cloud-openfeign/branch/3.1.x/graph/badge.svg["Codecov", link="https://app.codecov.io/gh/spring-cloud/spring-cloud-openfeign/tree/3.1.x"]
 
 image:https://api.codacy.com/project/badge/Grade/97b04c4e609c4b4f86b415e4437a6484["Codacy code quality", link="https://www.codacy.com/app/Spring-Cloud/spring-cloud-openfeign?utm_source=github.com&utm_medium=referral&utm_content=spring-cloud/spring-cloud-openfeign&utm_campaign=Badge_Grade"]