Declare implicit dependency on Six 1.9 or higher

[amorde]

This project uses a syntax for importing urllib.parse from six which was introduced in Six version 1.4

The import can be found here

The relevant change in Six can be found here

This can cause an issue if a project has a previous version of Six (say version 1.3) installed when installing html5lib

EDIT:
importing viewkeys in html5parser.py requires six 1.9

[jayvdb]

I need this for #294.

[jayvdb]

It would be nice to have a test job that explicitly requires and uses six 1.4 , so that newer features are not inadvertently used without upgrading the requirement.

[amorde]

@jayvdb That sounds like a great idea, I'm not really sure how to go about doing that though.

[jayvdb]

You could add a job with

 env:
   - USE_OPTIONAL=true
   - USE_OPTIONAL=false
+  - USE_SIX_14=true

And then in requirements-install.sh look for that flag and force install 1.4 (and if anything upgrades it to a more recent version, fix it).

[amorde]

@jayvdb It appears the minimum required version is actually 1.9. Good call on the testing thing.

I'll squash these commits and do a force push

[jayvdb]

In addition to the Travis errors described in #298, you are introducing many additional Travis jobs per build. This problem only requires one additional job.

[jayvdb]

Unnecessary jobs created.

[jayvdb]

The commits probably need squashing.

[jayvdb]

USE_SIX_LOWEST_VERSION is very long. Could be shorter.

[amorde]

Changed to SIX_VERSION

[amorde]

Hey @jayvdb, any updates on this?

[jayvdb]

@amorde , I am not a committer here. I can only do code review, which I have done.
I am also waiting for this to be reviewed/merged so that I can complete #294. ;-)

[amorde]

@jayvdb gotcha, haha sorry for the mixup!

[gsnedders]

Thanks for the reviewing, @jayvdb! :)

Ultimately, we should almost certainly declare (and test) minimum required versions for all our dependencies.