Apple Swift version 4.1.2 (swiftlang-902.0.54 clang-902.0.39.2)
Target: x86_64-apple-darwin17.5.0

Issue Description:

When formatting array/dictionary literals that have a trailing comma after their final element, SourceKit indents closing brackets to the same level as the elements instead of the opening line.

Steps to reproduce:

Minimal example.swift file:

struct TheStruct {
    let anArray = [
        1,
        2,
    ]
}

Run: sourcekitten format --file example.swift

Expected behaviour: The above format is already correct, contents should be unchanged.
Actual behaviour: The closing "]" is indented to the same level as the "2,".