Try to get Travis-CI back online

[ocefpaf]

Similar to ODM2/WOFpy#65 this should be reviewed, and hopefully tested, by someone with experience ODM2PythonAPI internals.

Currently Travis-CI is not running due to many errors that happens before the tests section. In this PR I tried to clean the configuration and the dependencies definition, which happened in multiple places, to get Travi-CI working again.

I could get to the test phase but now we have to deal with some, I beileve, genuine failures:

13 failed, 42 passed, 109 skipped, 1 pytest-warnings, 10 error in 7.71 seconds 

I also added a section for Pythons 3.4, 3.5, 3.6 and coding standards, but I marked them as expected failures because a huge effort is needed to bring those up to speed.

PS: I will take a look as AppVeyor testing in another PR.

[emiliom]

@ocefpaf, FYI, I'll leave this dormant for a while longer. Besides, given major PR's merged recently, this PR may need to be withdrawn and redone?

We can start working on TravisCI testing after #72 is handled and a new release is issued. So, not not 😉

[ocefpaf]

@ocefpaf, FYI, I'll leave this dormant for a while longer. Besides, given major PR's merged recently, this PR may need to be withdrawn and redone?

There are no conflict merges so I don't think we need a new one. But it does need a few hours of work to get it back online. (And a few extra to make get the tests to actually pass 😄 )