Description of problem:
copr plugin fails to load

Version-Release number of selected component (if applicable):
dnf-0.5.2-1.fc20.noarch
dnf-plugins-core-0.1.0-2.fc20.noarch

How reproducible:
On fresh Fedora 20 install 

Steps to Reproduce:
1. Install F20
2. Install dnf and dnf-plugins-core
3. Run dnf copr

Actual results:
# LANG=C dnf -v copr
Config time: 0.006
cachedir: /var/cache/dnf/x86_64/20
Failed loading plugin: copr
Loaded plugins: debuginfo-install, download, builddep, generate_completion_cache, noroot, kickstart, Query
initialized DebuginfoInstall plugin
initialized BuildDep plugin
initialized Noroot plugin
Initialized Query plugin
dnf version: 0.5.2
No such command: copr. Please use /bin/dnf --help
Cleaning up.


Expected results:
# LANG=C dnf -v copr
Config time: 0.006
cachedir: /var/cache/dnf/x86_64/20
Loaded plugins: debuginfo-install, download, builddep, generate_completion_cache, noroot, kickstart, copr, playground, Query
initialized DebuginfoInstall plugin
initialized BuildDep plugin
initialized Noroot plugin
initialized Copr plugin
initialized Playground plugin
Initialized Query plugin
dnf version: 0.5.2
Error: exactly two additional parameters to copr command are required
 Mini usage:

copr 
  enable name/project [chroot]
  disable name/project
  list name
  search project

  Examples:
  copr enable rhscl/perl516 epel-6-x86_64
  copr enable ignatenkobrain/ocltoys
  copr disable rhscl/perl516
  copr list ignatenkobrain
  copr search tests
    

Interact with Copr repositories.
Error: exactly two additional parameters to copr command are required
Cleaning up.

Additional info:
copr plugin needs python-requests, while dnf-plugins-core does not require it

Permission to fix this?