Added new method to repository API to get the archive of the repository

src/main/java/com/messners/gitlab/api/RepositoryApi.java

 package com.messners.gitlab.api;
 
+import java.io.InputStream;
 import java.util.List;
 
 import javax.ws.rs.core.Form;
@@ -220,4 +221,22 @@ public class RepositoryApi extends AbstractApi {
         Response response = get(Response.Status.OK, null, "projects", projectId, "repository", "raw_blobs", sha);
         return (response.readEntity(String.class));
     }
+
+    /**
+     * Get an archive of the complete repository by SHA (optional).
+     *
+     * GET /projects/:id/repository/archive
+     *
+     * @param projectId
+     * @param sha
+     * @return an input stream that can be used to save as a file
+     * or to read the content of the archive
+     * @throws GitLabApiException
+     */
+    public InputStream getRepositoryArchive(Integer projectId, String sha) throws GitLabApiException {
+        Form formData = new Form();
+        addFormParam(formData, "sha", sha, false);
+        Response response = get(Response.Status.OK, formData.asMap(), "projects", projectId, "repository", "archive");
+        return (response.readEntity(InputStream.class));
+    }
 }