[jsk_tools] Add documentation for restart_travis

jsk_tools/README.md

@@ -72,6 +72,25 @@ set ROS_MASTER_URI to http://baxter:11311
 ```
 
 
+restart\_travis
+---------------
+Restart travis for specified github repository.
+Firstly, add below in your `.bashrc`:
+
+```sh
+# you can get SLACK_TOKEN at https://api.slack.com/web.
+export SLACK_TOKEN=xoxp-XXXXXXXX-XXXXXXXX-XXXXXXXX
+export SLACK_USERNAME=hogehoge
+```
+
+To restart travis, need the repository slug (ex: `jsk-ros-pkg/jsk_common`) and job id (ex: `2019.6`):
+
+```sh
+$ restart_travis jsk-ros-pkg/jsk_common 2019.6  # usage: restart_travis <repo_slug> <job_id>
+sending... 'restart travis jsk-ros-pkg/jsk_common 2019.6' -> #travis
+```
+
+
 # sanity_lib.py
 ## check Topic is published