.github: [jepsen] source .bashrc (#6139)
fixes https://github.com/tendermint/tendermint/runs/1926771645
```
ERROR [2021-02-18 12:16:30,492] main - jepsen.cli Oh jeez, I'm sorry,
Jepsen broke. Here's why:
clojure.lang.ExceptionInfo: throw+: {:dir "/", :private-key-path nil,
:password "root", :username "root", :type :jepsen.control/session-error,
:port 22, :strict-host-key-checking false, :host nil, :sudo nil, :dummy
false, :message "Error opening SSH session. Verify username, password,
and node hostnames are correct.", :session nil}
```