[WIP] more testing of successful ezupload (no bug) re #2

* test coverage of "success" branch of ezupload.
* it's gross that `ezupload` promises different things depending on what
happens...
  - data clear
  - the death of the addon
  - res

SHOULD IT CLEAR?  SHOULD IT KILL?
conclusive tests that config survives restarts  (really fix #27)

* new make target "test-shell" for bash related tests.
* shows that a study config is maintained across a true firefox restart
  (we could do even further along this path, if we need to).
* Mechanism.  start and kill fx with a study.  Start it again,
  and show second time study has same personid and starttime (which it
  will revive out of simple-storage.micropilot.<<studyname>>