Long type can represent longer numbers

[DifferentialOrange]

Description says

graphql/graphql/types.lua

Line 311 in cd0f6e4

"Long can represent values from -(2^52) to 2^52 - 1, inclusive.",

(Same here: https://github.com/tarantool/graphql/wiki/Long)

But in fact Long can work with LL/ULL types and represent larger values

graphql/graphql/types.lua

Lines 289 to 293 in cd0f6e4

	if ffi.istype('int64_t', value) then
	return true
	elseif ffi.istype('uint64_t', value) then
	return value < 2^63
	end

See also #55