Ignore shallow clone coverage on appveyor

DanielChabrowski · DanielChabrowski · commit ab1df034182b · 2019-03-16T00:16:42.000+01:00
Appveyor uses old version of git so shallow clone
always fails and lines 150-151 are not executed.
diff --git a/pre_commit/store.py b/pre_commit/store.py
@@ -142,7 +142,7 @@ def _complete_clone(self, ref, git_cmd):
         git_cmd('checkout', ref)
         git_cmd('submodule', 'update', '--init', '--recursive')
 
-    def _shallow_clone(self, ref, git_cmd):
+    def _shallow_clone(self, ref, git_cmd):  # pragma: windows no cover
         """Perform a shallow clone of a repository and its submodules """
 
         git_config = 'protocol.version=2'
