test: make git example clone local repo

Author: tydeu

Diff for: examples/git/lakefile.lean

@@ -4,8 +4,8 @@ open System Lake DSL
 
 package git_hello
 
-require hello from git
-  "https://github.com/leanprover/lake.git"@"master"/"examples"/"hello"
+require hello from
+  git "../.."@"master"/"examples"/"hello"
 
 @[defaultTarget]
 lean_exe git_hello {