Don't crash if the connection has an error
set encrypted flag to None for root device

"AWS API doesn't support any value for this flag for the root device of
a new instance"

see: boto#2587

closes gh-455
move try/except from is_up to is_ssh_up
Merge branch 'fix-conn-reset-by-peer' into develop

closes #465
Updated readme
Fixed readme
remove t2 types from placement group types list
bump version to 0.95.6
Changelog: update for 0.95.6 release
Merge branch 'hotfix-0.95.6' into develop
Update .travis.yml
README got travis build status
Removed tests over python 2.6
Merge branch 'develop' of git://github.com/jtriley/StarCluster into vanilla_improvements

Conflicts:
	starcluster/static.py
Removed unused import
Travis run check.py
Added pep8 to travis
Added pyflakes to travis
Removed datacratic plugins from vanilla template
Merge branch 'vanilla_improvements' of github.com:datacratic/StarCluster into datacratic_dev