Does not work on Python 2.7 ?

[kinverarity1]

(I had a bug report for lasio which turned out to be for welly)

On the readme welly is described as supporting python 2.7 but I notice that the tests are failing for 2.7 (although showing as passed?).

I've submitted PR #82 which provides python 2.7 compatibility with only a few minor changes, apart from one test which fails due to a lack of 2.7 support in striplog.

[kinverarity1]

The striplog bug for py2.7 is here: https://github.com/agile-geoscience/striplog/issues/91