Fix problem with excluding .git files

Fixes issue as illustrated in error ouput:
```
version -t deb --maintainer someone@example.com --plugin=puppetforge --modulename=example42/network
Notice: Preparing to install into /tmp/tmp63lMsH ...
Notice: Downloading from https://forge.puppetlabs.com ...
Notice: Installing -- do not interrupt ...
/tmp/tmp63lMsH
└─┬ example42-network (v3.1.5)
  ├── example42-stdmod (v0.0.4)
  ├── puppetlabs-concat (v1.1.0)
  └── puppetlabs-stdlib (v4.2.1)
All flags should be before the first argument (stray flags found: ["--exclude=tests/*", "--exclude=spec/*", "-t", "--maintainer"] {:level=>:warn}
Missing required -t flag. What package output did you want? {:level=>:warn}
Fix the above problems, and you'll be rolling packages in no time! {:level=>:fatal}
Traceback (most recent call last):
  File "/usr/local/bin/version", line 9, in <module>
    load_entry_point('vdt.version==0.1.1', 'console_scripts', 'version')()
  File "/usr/local/lib/python2.7/dist-packages/vdt/version/main.py", line 58, in main
    run(args, extra_args)
  File "/usr/local/lib/python2.7/dist-packages/vdt/version/main.py", line 26, in run
    sys.exit(repo.build_package(version))
  File "/usr/local/lib/python2.7/dist-packages/vdt/version/repo.py", line 62, in build_package
    return self.call_plugin_function('build_package', version)
  File "/usr/local/lib/python2.7/dist-packages/vdt/version/repo.py", line 26, in call_plugin_function
    return function(*args, **kwargs)
  File "/usr/local/lib/python2.7/dist-packages/vdt/versionplugin/puppetforge/package.py", line 37, in build_package
    create_package("puppet-%s" % modulename, modulename, str(version), extra_args)
  File "/usr/local/lib/python2.7/dist-packages/vdt/versionplugin/puppetmodule/shared.py", line 42, in create_package
    subprocess.check_call(cmd)
  File "/usr/lib/python2.7/subprocess.py", line 540, in check_call
    raise CalledProcessError(retcode, cmd)
subprocess.CalledProcessError: Command '['fpm', '-s', 'dir', '--depends=puppet-common', '--prefix=/etc/puppet/modules/network', '--architecture=all', '--name=puppet-network', '--version=3.1.5', '--config-files=/etc/puppet/modules/network/files/spec.conf', '--config-files=/etc/puppet/modules/network/files/.gitkeep', '--config-files=/etc/puppet/modules/network/data/common.yaml', '--config-files=/etc/puppet/modules/network/data/osfamily/.gitkeep', '--config-files=/etc/puppet/modules/network/templates/route_down-Debian.erb', '--config-files=/etc/puppet/modules/network/templates/hostname-RedHat.erb', '--config-files=/etc/puppet/modules/network/templates/spec.conf', '--config-files=/etc/puppet/modules/network/templates/route_up-Debian.erb', '--config-files=/etc/puppet/modules/network/templates/route-RedHat.erb', '--config-files=/etc/puppet/modules/network/templates/hostname-Debian.erb', '--config-files=/etc/puppet/modules/network/templates/.gitkeep', '--config-files=/etc/puppet/modules/network/templates/interface/RedHat.erb', '--config-files=/etc/puppet/modules/network/templates/interface/Suse.erb', '--config-files=/etc/puppet/modules/network/templates/interface/Debian.erb', '--config-files=/etc/puppet/modules/network/manifests/interface.pp', '--config-files=/etc/puppet/modules/network/manifests/params.pp', '--config-files=/etc/puppet/modules/network/manifests/route.pp', '--config-files=/etc/puppet/modules/network/manifests/conf.pp', '--config-files=/etc/puppet/modules/network/manifests/init.pp', '--exclude=spec/classes/*', '--exclude=spec/system/*', '.gitkeep', '--exclude=tests/*', '--exclude=spec/*', '-t', 'deb', '--maintainer', 'someone@example.com', 'files/spec.conf', 'files/.gitkeep', 'data/common.yaml', 'data/osfamily/.gitkeep', 'templates/route_down-Debian.erb', 'templates/hostname-RedHat.erb', 'templates/spec.conf', 'templates/route_up-Debian.erb', 'templates/route-RedHat.erb', 'templates/hostname-Debian.erb', 'templates/.gitkeep', 'templates/interface/RedHat.erb', 'templates/interface/Suse.erb', 'templates/interface/Debian.erb', 'manifests/interface.pp', 'manifests/params.pp', 'manifests/route.pp', 'manifests/conf.pp', 'manifests/init.pp']' returned non-zero exit status 1
```