[gnome-screenshot: 1/2] updated the GTK+ dependecy

[Cosimo Cecchi <cosimoc src gnome org>]

commit ff31aba8daa52b0ec46c53991d90fd6a99f83603
Author: Torben Andresen <torben andresen tapsiturtle net>
Date:   Tue Jan 29 07:49:53 2019 +0000

    updated the GTK+ dependecy

 README.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/README.md b/README.md
index 075779e..4c9917f 100644
--- a/README.md
+++ b/README.md
@@ -7,6 +7,6 @@ desktop; the currently focused window; or an area of the screen.
 ### Dependencies
 
  - GLib 2.36
- - GTK+ 3.0
+ - GTK+ 3.12
  - libcanberra-gtk3
  - X11