Support wildcards in tag option

Close #427

README.md

@@ -89,6 +89,9 @@ Plug 'tpope/vim-fireplace', { 'for': 'clojure' }
 " Using a non-master branch
 Plug 'rdnetto/YCM-Generator', { 'branch': 'stable' }
 
+" Using a tagged release; wildcard allowed (requires git 1.9.2 or above)
+Plug 'fatih/vim-go', { 'tag': '*' }
+
 " Plugin options
 Plug 'nsf/gocode', { 'tag': 'v.20150303', 'rtp': 'vim' }