Merge branch 'patch-3' into 'master'

Update kubernetes.md - fix typo for bearer_token

See merge request gitlab-org/gitlab-runner!1162

docs/executors/kubernetes.md

@@ -91,7 +91,7 @@ The following keywords help to define the behaviour of the Runner within Kuberne
 - `service_account_overwrite_allowed`: Regular expression to validate the contents of
   the service account overwrite environment variable. When empty,
     it disables the service account overwrite feature
-- `bearer-token`: Default bearer token used to launch build pods.
+- `bearer_token`: Default bearer token used to launch build pods.
 - `bearer_token_overwrite_allowed`: Boolean to allow projects to specify a bearer token that will be used to create the build pod.
 - `volumes`: configured through the config file, the list of volumes that will be mounted in the build container. [Read more about using volumes.](#using-volumes)