Fix make check for python 3

[mikemadden42]

make check works fine on Ubuntu 18.04 after this fix.

[kvch]

It does not seem to fix the build. :(

[mikemadden42]

Thanks @kvch . I'm guessing you're referring to the travis-ci jobs?

I wonder if this is an issue with an older Python in Travis CI? @jsoriano Is there a minimum python 3.x that we're targeting?

DEPRECATION: Python 3.4 support has been deprecated. pip 19.1 will be the last one supporting it. Please upgrade your Python as Python 3.4 won't be maintained after March 2019 (cf PEP 429).

[mikemadden42]

I wonder if we need to update the version of Ubuntu used for our travis-ci jobs. We're using Ubuntu 14.04 (Trusty) which looks like it ships with Python 3.4. We may need to switch to Ubuntu 16.04 (Xenial) or 18.04 (Bionic). I've been doing my testing on Ubuntu 18.04.

$ grep ^dist .travis.yml
dist: trusty

[mikemadden42]

@kvch @jsoriano make check is passing in the latest travis build for this PR.

https://travis-ci.org/elastic/beats/builds/627459709

[jsoriano]

Thanks! If travis likes it, I like it!

I wonder if this is an issue with an older Python in Travis CI? @jsoriano Is there a minimum python 3.x that we're targeting?

We haven't decided a minimum version to support, but in any case we shouldn't care about deprecated or unmaintained versions, so no worries if this doesn't work with Python 3.4.

There was a point about upgrading python, or the base image in Travis in #14798, I have added this PR as fix for that.

[mikemadden42]

There are around 11 failures unrelated to make check in the last travis build. It would be nice to investigate these.

https://travis-ci.org/elastic/beats/builds/627459709