setuptools deprecations

Index: setup.cfg
--- setup.cfg.orig
+++ setup.cfg
@@ -7,11 +7,11 @@
 
 [install]
 verbose=1
-install-scripts=$base/bin
-install-platlib=$base/lib/mypaint
-install-purelib=$base/lib/mypaint
-install-data=$base/share
-install-headers=$base/include
+install_scripts=$base/bin
+install_platlib=$base/lib/mypaint
+install_purelib=$base/lib/mypaint
+install_data=$base/share
+install_headers=$base/include
 
 [nosetests]
 with-doctest=1
