Merge pull request #287 from guanqun/add-git-suffix-to-submodule

add .git suffix to the submodule url

Author: alexcrichton

.gitmodules

@@ -1,3 +1,3 @@
 [submodule "curl-sys/curl"]
 	path = curl-sys/curl
-	url = https://github.com/curl/curl
+	url = https://github.com/curl/curl.git