* have lint target run shellcheck over tests
* lint and fix tests/ since shellcheck knows bats
* lint and fix tests/ since shellcheck knows bats
* revert debug output
* changes for shellcheck
* revert unintended change
[tests/_test_base.bash]
* use 'local' for user/filename vars, not 'export'
* add note about Shellcheck and tests/
* local can only be used in functions - use export
* restore shbang edited in error
* code style in CONTRIBUTING.md and PR template
* make link to CONTRIBUTING.md in .github/PULL_REQUEST_TEMPLATE.md
* mention shellcheck and 'make lint'
* mention that you should update CHANGELOG.md
* mention spellchecking with aspell
* more spelling fixes
* add to CHANGELOG about style guide/dev philosophy
* remind contributors to update .ronn file/man page
* test that hiding secret with expired key fails
* add test of user key without username.
* revert to performing most tests with 'user1'.
* move user4 private/public key fixtures
* factor code fetching emails from keyrings, add comments.
* use factored _warn_or_abort()
* add to, clean up, and clarify comments.
Changes:
1. Now everything is tested inside the `docker`-containers and `OSX` images on `travis`.
2. We now have `CONTRIBUTING.md` and `LICENSE.md`. `README.md` is also changed.
3. We have a brand logo.
4. We have autodeploy to `bintray`.
5. Everything is `shellcheck`ed (except `tests/`).
Closes#32#33#34#35#39
