Update inspect.lua

Allow passing the option `excludeMeta` to blindly skip printing the metatable info like `inspect(t, {excludeMeta=true})`. This is useful for printing clean debug information on things like higher-level 'data type' wrappers. Ie - printing the contents of a python dict-like object

`function dict:keys()
    local keys = _.keys(self.__items__)
    setmetatable(keys, {
        __tostring = function()
            return inspect(keys, {excludeMeta=true})
        end
    })
    return keys
end`