Slaves file is now a template.

Change 0dc868e7 removed the `conf/slaves` file and made it a template like most of the other configuration files. This means you can no longer run `make-distribution.sh` unless you manually create a slaves file to be statically bundled in your distribution, which seems at odds with making it a template file.

Author: Sarah Gerweck <sarah.a180@gmail.com>

Closes #2549 from sarahgerweck/noMoreSlaves and squashes the following commits:

d11d99a [Sarah Gerweck] Slaves file is now a template.

make-distribution.sh

@@ -201,7 +201,6 @@ fi
 # Copy other things
 mkdir "$DISTDIR"/conf
 cp "$FWDIR"/conf/*.template "$DISTDIR"/conf
-cp "$FWDIR"/conf/slaves "$DISTDIR"/conf
 cp "$FWDIR/README.md" "$DISTDIR"
 cp -r "$FWDIR/bin" "$DISTDIR"
 cp -r "$FWDIR/python" "$DISTDIR"