prepare for 0.10.0 release

## todo

- [ ] @krukow Can you update the README.md or changelog/0.10.0.md with some notes about lib frank?  If at all possible, please add commits to this PR.  Thanks!

- [ ] @jmoody First pass at documenting the env. vars. that calabash uses.
- [ ] @jmoody Local testing of proposed gemspec changes (not in the change set yet).