Add EPEL dependency

As PlanEx needs mock, it needs EPEL. Adding instructions to README on
how to install them.

fixes xenserver/planex#50
Merge pull request #51 from matelakat/add-epel

Add EPEL dependency
build: Use mock by default

Fixes https://github.com/xenserver/planex/issues/55

Signed-off-by: Euan Harris <euan.harris@citrix.com>
Merge pull request #56 from euanh/patchqueue

build: Use mock by default
Implement SpecTemplate.sources

To get the ordered list of all Sources within them spec template.

related to xenserver/planex#53
Rename GitHubSource to GitSource

To prepare this source to be relaxed from github constraints.

related to xenserver/planex#53
GitSource: relax path restrictions

GitSource can now clone deeper hierarchies.

related to xenserver/planex#53
planex-clone doesn't deal with branches

The clone command should not be responsible for checking out the branch,
it should just clone the repository.

related to xenserver/planex#53
Recognise Source: fragment

SimpleRPM will be able to recognise Source: as Source0:

related to xenserver/planex#53
planex-clone will process all the sources

related to xenserver/planex#53
planex-clone: throw away non-recognised sources

related to xenserver/planex#53
Make sure .git is only appended if needed

When creating local clones for a URL which already ends with .git,
planex-clone will not append an additional .git to it.

related to xenserver/planex#53