#49 Fix format problem with empty objects

[Max Bruckner]

When printing empty objects, the closing curly brace was missing one
indentation level.

Example from the output of test_utils:

BEFORE FIX:
{
"foo": "bar",
"child": {
"grandchild": {
}
}
}

AFTER FIX:
{
"foo": "bar",
"child": {
"grandchild": {
}
}
}

[Dave Gamble]

Again, merged upstream (thanks to you and kbranigan! :)