[epiphany] gitignore both build/ and _build/

[Michael Catanzaro <mcatanzaro src gnome org>]

commit 65b830673863ff275b30ed425826ae1f3e8e3d05
Author: Michael Catanzaro <mcatanzaro gnome org>
Date:   Wed May 20 10:41:58 2020 -0500

    gitignore both build/ and _build/
    
    Since we can't seem to agree on a standard build directory, let's ignore
    them both and make everyone happy. See !675.

 .gitignore | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/.gitignore b/.gitignore
index 69fa449dd..2907da99f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
 _build/
+build/