Remove duplicated requirements information

All requirements information held in setup.py.  CI runs `python setup.py
test` to install and test.

Fixes #9.
Only run rembed tests
Merge pull request #11 from matt-thomson/issue9

Fixes #9.
Test against multiple Python versions

Also tidy .travis.yml
Drop unsupported Python versions
Fix Python 3.x incompatibilites
Merge pull request #12 from matt-thomson/issue3

Support more Python versions
Add MANIFEST.in

Include license and readme
Add changelog
Add to README
Full license in setup.py
Add some classifiers
Merge pull request #13 from matt-thomson/issue10

Improve PyPI package entry.  

Closes #10.
Add support for max height and width parameters
Compatibility fixes for Python 3

Also includes more consistent ordering of query parameters
Merge pull request #15 from matt-thomson/issue4

Add maxheight and maxwidth parameters

Closes #4
Changelog for v0.2.0
Add compatibility note
Deploy only once
Set version to 0.2.0