[gtksourceview] Add breakpoint function from Python 3.7

[Christian Hergert <chergert src gnome org>]

commit febdaa7b2567ddfd1e6aa3ad347540c448932bd9
Author: Jonathan <jonathan foreningshuset se>
Date:   Mon Sep 17 16:22:59 2018 +0000

    Add breakpoint function from Python 3.7

 data/language-specs/python3.lang | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/data/language-specs/python3.lang b/data/language-specs/python3.lang
index 1ab853b0..e36f4422 100644
--- a/data/language-specs/python3.lang
+++ b/data/language-specs/python3.lang
@@ -184,6 +184,7 @@
           <prefix>(?&lt;![\w\.])</prefix>
           <keyword>ascii</keyword>
           <keyword>bin</keyword>
+          <keyword>breakpoint</keyword>
           <keyword>bytearray</keyword>
           <keyword>bytes</keyword>
           <keyword>exec</keyword>