[#51] Remove float type and always use the decimal type
[#51] Fix bad test. It was bad because it returned the same result for Decimal and for Int.
Merge branch 'master' into 51-remove-float-type

Conflicts:
	messytables/types.py
[#51] Update changelog
[#51] Fix problems with Python 2.6 and decimal
Merge pull request #51 from okfn/51-remove-float-type

DecimalType vs FloatType