Drop support for PyTables < 3.0.0

[cpcloud]

This makes CI much easier (probably faster) and is less of a maintenance burden.

• pep8 method/function calls where necessary in io/pytables.py (maybe tests too)

[jreback]

ok pytables all for this

I'll wait for u to fix up the conda stuff

or u want me to do this first?

you are doing conda first them numpy right?
(or sort of at same time)

[cpcloud]

doing the numpy first to get rid of those imports ... then conda then i'll do this

[cpcloud]

there's just one failure left for py26 np17 then will be good 2 go

[jreback]

ok cool

I can do the pytables change it's pretty straightforward

[cpcloud]

okie doke go 4 it

[jreback]

I had to bump numexpr to min of 2.1 as well (no biggie though)

[cpcloud]

np