Add some instructions on configuring sendmail.
#322: Automatically disable outgoing emails during Drush unit tests
Merge branch 'auto_sendmail_path' into sendmail_path
Remove unnecessary instructions
Fix for issue #95.

- Adds an 'ignore' option to `release_info_fetch` that is used by drush
  make when only project type is needed from release info.
Support D8 in cache-get per #233.
Merge pull request #322 from greg-1-anderson/sendmail_path

Automatically disable outgoing email during unit tests
Issue #95: Use drush_set_error instead of user_abort.
Merge pull request #327 from drush-ops/make-default-project-type

New option to ignore official release status
Use drush_include_engine() instead of checking --user option.
 Add “rebuild” command for Drupal 8; have it replace drush cache-clear all.
Add instructions for using php 5.5 to README.md