remove ec_git_vsn_test

This test only had one test that dependended entirely on the
state of *this* git repository. Tests shouldn't depend on external
unmanaged state not changing.

test/ec_git_vsn_tests.erl

@@ -1,15 +0,0 @@
--module(ec_git_vsn_tests).
--include_lib("eunit/include/eunit.hrl").
--compile([export_all]).
-
-
-%% Hi! This test only works because you've cloned this repo out of git
-%% AND we're tagging this repo with a "v" prefix. Hey, it's better
-%% than nothing.
-vsn_grep_test() ->
-    {ok, VSN} = ec_git_vsn:vsn({"v"}),
-
-    [$v|OtherVSN] = os:cmd("git tag | xargs -I@ git log --format=format:\"%ai @%n\" -1 @ | sort -r | awk '{print $4}' | head -n 1"),
-
-    ?assertEqual(OtherVSN, VSN ++ "\n"),
-    ok.