[pygobject] Add Ubuntu dependencies for dev environment

[Christoph Reiter <creiter src gnome org>]

commit 7f5d8b08f7085ba1eec95f17d690d5d4b10902b8
Author: Dan Yeaw <dan yeaw me>
Date:   Fri Apr 13 22:09:03 2018 -0400

    Add Ubuntu dependencies for dev environment
    
    Signed-off-by: Dan Yeaw <dan yeaw me>

 docs/devguide/dev_environ.rst | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/docs/devguide/dev_environ.rst b/docs/devguide/dev_environ.rst
index 3e0db366..265a551f 100644
--- a/docs/devguide/dev_environ.rst
+++ b/docs/devguide/dev_environ.rst
@@ -35,10 +35,10 @@ your operating system.
 
 .. code:: console
 
-    sudo apt-get install -y python3-venv python3-wheel
+    sudo apt-get install -y python3-venv python3-wheel python3-dev
     sudo apt-get install -y libgirepository1.0-dev build-essential \
       libbz2-dev libreadline-dev libssl-dev zlib1g-dev libsqlite3-dev wget \
-      curl llvm libncurses5-dev libncursesw5-dev xz-utils tk-dev
+      curl llvm libncurses5-dev libncursesw5-dev xz-utils tk-dev libcairo2-dev
 
 
 .. _fedora-dep: