Switch to using git submodules for the yaml tests

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "test_elasticsearch/rest-api-spec"]
+	path = test_elasticsearch/rest-api-spec
+	url = https://github.com/elasticsearch/elasticsearch-rest-api-spec.git

test_elasticsearch/test_server/test_common.py

@@ -188,8 +188,8 @@ YAML_DIR = environ.get(
     'YAML_TEST_DIR',
     join(
         dirname(__file__),
-        pardir, pardir, pardir,
+        pardir, 
-        'elasticsearch-rest-api-spec', 'test'
+        'rest-api-spec', 'test'
     )
 )
 

tox.ini

@@ -1,6 +1,9 @@
 [tox]
 envlist = pypy,py26,py27,py33
 [testenv]
+whitelist_externals = git
 setenv =
     NOSE_XUNIT_FILE = junit-{envname}.xml
-commands = python setup.py test
+commands =
+    git submodule init
+    python setup.py test