Use value of region when determining default endpoint value.

References #27
Revert README sections.
Update YAML examples to use modern syntax in README.
Remove require_chef_omnibus & sudo documentation from README.

These are now Provisioner concerns.
Update project links in README.
endpoint should have a trailing slash per https://github.com/fog/fog/issues/583
Merge pull request #31 from spheromak/master

endpoint should have a trailing slash
Support AWS session tokens for use with IAM roles.
Merge pull request #34 from coderanger/master

Support AWS session tokens for use with IAM roles.
Add: pry is handy to have around
Add: test coverage for interface choice logic
Add: allow setting of hostname via config or fallback
Add: we need rspec
Add: update documentation
Fix: We do not want to load pry in the driver unless debugging
Change: Allow lines to be 100 chars long
Change: Allow lines to be 100 chars long
Change: refactor according to style guidelines
Change: use single quotes
Change: refactor according to style guidelines