python/pluggy: Added support python3.

Signed-off-by: Dimitris Zlatanidis <d.zlatanidis@gmail.com>

python/pluggy/README

@@ -2,3 +2,5 @@ pluggy (mechanisms for python)
 
 This is the plugin manager as used by pytest but stripped of pytest
 specific details.
+
+Optional dependency: python3

python/pluggy/pluggy.SlackBuild

@@ -71,6 +71,11 @@ find -L . \
 
 python setup.py install --root=$PKG
 
+# Python 3 support.
+if $(python3 -c 'import sys' 2>/dev/null); then
+    python3 setup.py install --root=$PKG
+fi
+
 find $PKG -print0 | xargs -0 file | grep -e "executable" -e "shared object" | grep ELF \
   | cut -f 1 -d : | xargs strip --strip-unneeded 2> /dev/null || true