use latest pip on travis and enable caching

[thijstriemstra]

• also builds docs and does some pep8 checks on travis
• moved version number to central place in flickrapi/__version__.py
• lots of pep8 fixes (whitespace, missing lines etc)
• bump version to 2.3.2

[thijstriemstra]

This PR seems to reveal some test failures and broken coverage report:

Coverage.py warning: No data was collected. (no-data-collected)

[thijstriemstra]

ping @sybrenstuvel (you should enable github feature 'request review' for prs).

[sybrenstuvel]

I could make you collaborator, so that you can do that yourself. Would you like that?

[thijstriemstra]

sounds good, thx.

[coveralls]

Coverage decreased (-0.1%) to 71.156% when pulling dcc0fb6 on thijstriemstra:patch-1 into e3e5072 on sybrenstuvel:master.

[coveralls]

Coverage decreased (-0.1%) to 71.156% when pulling 32b5668 on thijstriemstra:patch-1 into e3e5072 on sybrenstuvel:master.

[coveralls]

Coverage decreased (-0.1%) to 71.156% when pulling 1c08119 on thijstriemstra:patch-1 into e3e5072 on sybrenstuvel:master.

[coveralls]

Coverage decreased (-0.1%) to 71.156% when pulling 9d6bbb6 on thijstriemstra:patch-1 into e3e5072 on sybrenstuvel:master.

[sybrenstuvel]

Nice work!

The requirements.txt file contains the exact versions of all the dependencies I use for testing, and provides a known-good set of version numbers. This also makes it possible to have multiple machines (owned by the same or different developers) all with a consistent set of dependencies. As such, it can't be replaced by just the version numbers in setup.py (which indicate minimum versions and/or upper limits to the versions for compatibility reasons, but not specific version numbers).

I do agree that those versions should be updated at some point.

[thijstriemstra]

@sybrenstuvel I will define the latest and greatest in setup.py then?

[sybrenstuvel]

No, define the minimum required versions in the setup.py. Don't increase them unless there is a very good reason to. Having those versions as low as possible makes it much easier for packaging with Linux distributions, 3rd party applications, etc. as they don't have to mess with their other packages when pulling in an update to the FlickrAPI library.

[coveralls]

Coverage decreased (-0.1%) to 71.156% when pulling 43c2cee on thijstriemstra:patch-1 into e3e5072 on sybrenstuvel:master.

[thijstriemstra]

@sybrenstuvel pinned the versions in setup.py

[sybrenstuvel]

I may not have been clear in my explanation. The versions should be mimimal versions, i.e. pkgname>=2.4, so that newer versions that have already been installed are also valid. requirements.txt should contain specific versions, i.e. pkgname==2.4.

[sybrenstuvel]

(version numbers there are for illustration only, they could very well be different)

[thijstriemstra]

@sybrenstuvel gotcha, see update.

[coveralls]

Coverage decreased (-0.1%) to 71.156% when pulling 29d84f5 on thijstriemstra:patch-1 into e3e5072 on sybrenstuvel:master.

[sybrenstuvel]

Better, but why still delete requirements.txt?

In travis.yml you put pip install --ignore-installed --upgrade setuptools pip tox-travis coveralls. What's the effect of having both --ignore-installed and --upgrade in one invocation? Don't they clash?

[coveralls]

Coverage decreased (-0.1%) to 71.156% when pulling c66396e on thijstriemstra:patch-1 into e3e5072 on sybrenstuvel:master.

[coveralls]

Coverage decreased (-0.1%) to 71.156% when pulling c66396e on thijstriemstra:patch-1 into e3e5072 on sybrenstuvel:master.

[thijstriemstra]

@sybrenstuvel restored the file and addressed your comments.

[sybrenstuvel]

Lots of good changes, thanks!