Fixed ebsimage bug

A snapshot id was being passed when a snapshot object was expected.

Caused this error:

earls3@jearls:~$ starcluster ebsimage i-14b2086a delete-me-10
StarCluster - (http://star.mit.edu/cluster) (v. 0.9999)
Software Tools for Academics and Researchers (STAR)
Please submit bug reports to starcluster@mit.edu

>>> Removing private data...
>>> Creating new EBS AMI...
>>> New EBS AMI created: ami-8345c7ea
>>> Fetching block device mapping for ami-8345c7ea
!!! ERROR - Error occurred while creating image
!!! ERROR - Unhandled exception occured
Traceback (most recent call last):
  File "/usr/local/lib/python2.6/dist-packages/StarCluster-0.9999-py2.6.egg/starcluster/cli.py", line 257, in main
    sc.execute(args)
  File "/usr/local/lib/python2.6/dist-packages/StarCluster-0.9999-py2.6.egg/starcluster/commands/ebsimage.py", line 61, in execute
    **self.specified_options_dict)
  File "/usr/local/lib/python2.6/dist-packages/StarCluster-0.9999-py2.6.egg/starcluster/awsutils.py", line 773, in create_ebs_image
    return icreator.create_image(size=root_vol_size)
  File "<string>", line 2, in create_image
  File "/usr/local/lib/python2.6/dist-packages/StarCluster-0.9999-py2.6.egg/starcluster/utils.py", line 91, in wrap_f
    res = func(*arg, **kargs)
  File "/usr/local/lib/python2.6/dist-packages/StarCluster-0.9999-py2.6.egg/starcluster/image.py", line 211, in create_image
    return self._create_image_from_ebs(size)
  File "/usr/local/lib/python2.6/dist-packages/StarCluster-0.9999-py2.6.egg/starcluster/image.py", line 241, in _create_image_from_ebs
    self.ec2.wait_for_snapshot(snap)
  File "/usr/local/lib/python2.6/dist-packages/StarCluster-0.9999-py2.6.egg/starcluster/awsutils.py", line 1032, in wait_for_snapshot
    log.info("Waiting for snapshot to complete: %s" % snap.id)
AttributeError: 'unicode' object has no attribute 'id'

!!! ERROR - Oops! Looks like you've found a bug in StarCluster
!!! ERROR - Crash report written to: /home/earls3/.starcluster/logs/crash-report-14437.txt
!!! ERROR - Please remove any sensitive data from the crash report
!!! ERROR - and submit it to starcluster@mit.edu
Added a list with the second generation instances

The 'SEC_GEN_TYPES' list contains the instances from the second generation EC2 instances, those instances have a HVM virtualization
Updated the _check_platform method

Added the second generation EC2 instances (m3) to the HVM instance check
travis: enable use_notice and skip_join for IRC
terminate: use log.warn on failure if --force

Minor logging fix in the case that loading cluster metadata fails but
user passed --force. In this case we change the error log to a warning
log given that the user wants to ignore the error and terminate anyway.
cluster: add support for userdata scripts
utils: add size_in_kb()

Calculates the size of a string in kilobytes
image: use ec2.get_snapshot to fetch snapshots
Merge branch 'pr/186' into develop

closes gh-186
static: add HVM_TYPES list

Contains a list of all types that support HVM AMIs. Currently this
includes CLUSTER_TYPES, HI_IO_TYPES, and SEC_GEN_TYPES.
cluster: simplify instance type/AMI validation code

Simplified the instance type/AMI validation in __check_platform by
making use of new static.HVM_TYPES. This refactoring results in the same
exact validation checks only it's *much* easier to read.
cluster: add m3 types to list of EBS-only types

The new m3.* types can only be used with EBS storage similar to micro
instances.
Merge branch 'pr/187' into develop

closes gh-187
Merge branch 'develop' of git://github.com/jtriley/StarCluster into datacratic_dev