Add ProjectBuild.erase()

We can't use the existing delete() functionality, because GitLab uses
`POST /projects/:id/builds/:build_id/erase` to erase a build. Instead of
overriding delete(), we add a separate erase() method to keep the naming
consistent, and allow potentially more fine-grained operations in the
future.

- https://docs.gitlab.com/ce/api/builds.html#erase-a-build

gitlab/exceptions.py

@@ -95,6 +95,10 @@ class GitlabBuildRetryError(GitlabRetryError):
     pass
 
 
+class GitlabBuildEraseError(GitlabRetryError):
+    pass
+
+
 class GitlabPipelineRetryError(GitlabRetryError):
     pass
 

gitlab/objects.py

@@ -961,6 +961,12 @@ def retry(self, **kwargs):
         r = self.gitlab._raw_post(url)
         raise_error_from_response(r, GitlabBuildRetryError, 201)
 
+    def erase(self, **kwargs):
+        """Erase the build (remove build artifacts and trace)."""
+        url = '/projects/%s/builds/%s/erase' % (self.project_id, self.id)
+        r = self.gitlab._raw_post(url)
+        raise_error_from_response(r, GitlabBuildEraseError, 201)
+
     def keep_artifacts(self, **kwargs):
         """Prevent artifacts from being delete when expiration is set.