Feature/filestorage sharenetworks create (#118)

* sfs: Add support for share networks Create

* sfs: Add Manila to acceptance test environment

* sfs: Add acceptance tests for share networks Create

* sfs: Remove unused urls

Some url functions were introduced but they belong to other
PRs. Will be repushed with in the correct PRs

* sfs: Make name and descr required for creating share network

* sfs: Remove required parameters

After taking a close look at the code it appeared that 'name'
and 'description' are not required parameters
diff --git a/openstack/sharedfilesystems/v2/sharenetworks/urls.go b/openstack/sharedfilesystems/v2/sharenetworks/urls.go
new file mode 100644
index 0000000..637ea98
--- /dev/null
+++ b/openstack/sharedfilesystems/v2/sharenetworks/urls.go
@@ -0,0 +1,7 @@
+package sharenetworks
+
+import "github.com/gophercloud/gophercloud"
+
+func createURL(c *gophercloud.ServiceClient) string {
+	return c.ServiceURL("share-networks")
+}