Fix install-dependencies.sh bug and cleanups (#720)
Fix install-dependencies.sh bug and cleanups (#720)

Was writing to PANOPTES_ENV_SH when it should have written to SHELL_RC.

Use /etc/os-release if available instead of lsb_release (which
is deprecated).

Remove unused checksum from install-dependencies.sh

Fix echo_bar so that it doesn't generate noisy error messages
when stdin isn't a terminal (i.e. something without a size).

panoptes/POCS,panoptes/POCS,panoptes/POCS,panoptes/POCS