Fixed grammer issue.

README.md

@@ -39,7 +39,7 @@ GitLabApi gitLabApi = new GitLabApi("http://your.gitlab.server.com", "YOUR_PRIVA
 List<Project> projects = gitLabApi.getProjectApi().getProjects();
 ```
 
-As of GitLab4J-API 4.2.0 support been added for GitLab API V4. If your application requires GitLab API V3 you can still use GitLab4J-API by creating your GitLabApi instance as follows:
+As of GitLab4J-API 4.2.0 support has been added for GitLab API V4. If your application requires GitLab API V3 you can still use GitLab4J-API by creating your GitLabApi instance as follows:
 ```java
 // Create a GitLabApi instance to communicate with your GitLab server using GitLab API V3
 GitLabApi gitLabApi = new GitLabApi(ApiVersion.V3, "http://your.gitlab.server.com", "YOUR_PRIVATE_TOKEN");