Program crashes if python3-setuptools is not installed

[Colin Wetherbee]

Invoking yamllint without python3-setuptools produces the following output.

$ yamllint /tmp/yaml
Traceback (most recent call last):
  File "/usr/bin/yamllint", line 5, in <module>
    from pkg_resources import load_entry_point
ImportError: No module named 'pkg_resources'

The yamllint package should include python3-setuptools as a dependency.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: yamllint 1.2.1-1
Uname: Linux 4.7.0-1-amd64 x86_64
ApportVersion: 2.20.1-0ubuntu2.1
Architecture: amd64
Date: Fri Nov 11 05:59:16 2016
ProcEnviron:
 TERM=screen-256color
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/usr/bin/zsh
SourcePackage: yamllint
UpgradeStatus: No upgrade log present (probably fresh install)