Merge pull request #18 from ccho-mongodb/update-redirects-1.7

update redirects file for 1.7

Author: Chris Cho

config/redirects

@@ -3,4 +3,4 @@ define: base https://docs.mongodb.com/php-library
 raw: php-library/ -> ${base}/current
 define version v1.1 v1.2 v1.3 v1.4 v1.5 v1.6 v1.7 master
 symlink: upcoming -> master
-symlink: current -> v1.6
+symlink: current -> v1.7