Project archiving and unarchiving (#152)

* project archiving and unarchiving
* expected response for archive and unarchive fixed
* remove unnecessary preconditions for archiving test

src/main/java/org/gitlab4j/api/ProjectApi.java

@@ -1853,4 +1853,34 @@ public class ProjectApi extends AbstractApi implements Constants {
         Response.Status expectedStatus = (isApiVersion(ApiVersion.V3) ? Response.Status.OK : Response.Status.NO_CONTENT);
         delete(expectedStatus, null, "projects", projectId, "share", groupId);
     }
+
+    /**
+     * Archive a project
+     *
+     * POST /projects/:id/archive
+     *
+     * @param projectId the ID of the project to archive, required
+     * @return the archived GitLab Project
+     * @throws GitLabApiException if any exception occurs
+     */
+    public Project archiveProject(Integer projectId)
+            throws GitLabApiException {
+        Response response = post(Response.Status.CREATED, (new GitLabApiForm()), "projects", projectId, "archive");
+        return (response.readEntity(Project.class));
+    }
+
+    /**
+     * Unarchive a project
+     *
+     * POST /projects/:id/unarchive
+     *
+     * @param projectId the ID of the project to unarchive, required
+     * @return the unarchived GitLab Project
+     * @throws GitLabApiException if any exception occurs
+     */
+    public Project unarchiveProject(Integer projectId)
+            throws GitLabApiException {
+        Response response = post(Response.Status.CREATED, (new GitLabApiForm()), "projects", projectId, "unarchive");
+        return (response.readEntity(Project.class));
+    }
 }

src/test/java/org/gitlab4j/api/TestProjectApi.java

@@ -440,6 +440,15 @@ public class TestProjectApi {
         gitLabApi.getProjectApi().unshareProject(project.getId(), shareGroup.getId());
     }
 
+    @Test
+    public void testArchiveProject() throws GitLabApiException {
+        Project project = gitLabApi.getProjectApi().getProject(TEST_NAMESPACE, TEST_PROJECT_NAME);
+        assertNotNull(project);
+
+        assertEquals(true, gitLabApi.getProjectApi().archiveProject(project.getId()).getArchived());
+        assertEquals(false, gitLabApi.getProjectApi().unarchiveProject(project.getId()).getArchived());
+    }
+
     @Test
     public void testGetOptionalProject() throws GitLabApiException {