Update .gitignore
Update .gitignore
retire quetzal, bring in tahr, change instance types on 64-bit machines.
fixing one incorrect instance type.
Merge pull request #1762 from kmarsteller/testhosts

Testhosts
fixing typo in testhosts.cfg
pinning to scipy 0.11.0 or higher; removing a machine from release testing.
Changing mkinstaller to reflect new scipy version pinning
fixing merge conflict in testhosts.cfg