Invalid json generated if table key is number

[inv2004]

Code:

import jsony, tables
let t = {100: "aaa"}.toTable
echo t.toJson

Actual:

{100:"aaa"}

^^^ json key uses quotes

Expected:

{"100":"aaa"}

[pietroppeter]

Probably the fix is to replace this dumpHook with a dumpKey:

jsony/src/jsony.nim

Line 792 in ea811be

s.dumpHook(k)