tests: allow "git version" test to pass on arbitrary git versions
tests: allow "git version" test to pass on arbitrary git versions

Sometimes people run development versions of git.
On these versions, "git version" returns, for example:

git version 1.5.4.rc2.1105.gfc5f2

The test_it_executes_git_to_shell_and_returns_result
testcase was updated to accept these versions of git.

Signed-off-by: David Aguilar <9de348c050f7cd1ca590883733c4e531ce610bf4@gmail.com>

StyXman/GitPython,Conjuro/GitPython,roidelapluie/GitPython,bwrsandman/GitPython,nvie/GitPython,zsjohny/GitPython,zsjohny/GitPython,gitpython-developers/GitPython,cdht/GitPython,gitpython-developers/gitpython,beni55/GitPython,roidelapluie/GitPython,cool-RR/GitPython,StyXman/GitPython,pengshp/GitPython,avinassh/GitPython,manasdk/GitPython,cool-RR/GitPython,dpursehouse/GitPython,expobrain/GitPython,avinassh/GitPython,nvie/GitPython,beni55/GitPython,breavo/GitPython,jeblair/GitPython,ghtdak/GitPython,gitpython-developers/GitPython,zsjohny/GitPython,cdht/GitPython,gitpython-developers/gitpython,expobrain/GitPython,OpenInkpot-archive/iplinux-python-git,h4ck3rm1k3/GitPython,Conjuro/GitPython,bwrsandman/GitPython,jeblair/GitPython,hvnsweeting/GitPython,cool-RR/GitPython,Conjuro/GitPython,pengshp/GitPython,cdht/GitPython,hvnsweeting/GitPython,StyXman/GitPython,breavo/GitPython,dpursehouse/GitPython,manasdk/GitPython,bwrsandman/GitPython,ghtdak/GitPython,pengshp/GitPython,h4ck3rm1k3/GitPython,avinassh/GitPython