fixes #273 - add support for new i3 instance types

[tamsky]

# pytest awslimitchecker/tests/services/test_ec2.py
=================================== test session starts ===================================
platform darwin -- Python 2.7.13, pytest-3.1.1, py-1.4.33, pluggy-0.4.0
rootdir: [elided]/src/github/awslimitchecker, inifile: pytest.ini
collected 28 items 

awslimitchecker/tests/services/test_ec2.py ............................

================================ 28 passed in 1.13 seconds ================================

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Signed-Off-By: tamsky@users.noreply.github.com Marc Tamsky

[tamsky]

Yes, I sorted the list of instance types in special_limits().

[jantman]

@tamsky thanks so much for this! The changes all look good to me, I'm just waiting for Travis to finish the tests. Assuming they're good I'll merge this now, and be targeting a new release in the next 7-8 days or so. I'll try for sooner if I can, but I want to get a few other issues handled in the next release as well.

[jantman]

The docs build is failing, but because of a file that wasn't touched in this diff. Merging.

[jantman]

This has been released as 0.9.0 and is now live on PyPI (CHANGELOG).