nested_args test is flaky

[SudoBobo]

Sometimes it fails, sometimes it passes. Maybe timeout time should be extended.

TAP version 13
1..2
not ok - 1
  ---
  filename: /Users/i.koptelov/IdeaProjects/graphql/test/space/nested_args.test.lua
  trace:
  - line: 80
    source: '@/Users/i.koptelov/IdeaProjects/graphql/test/space/nested_args.test.lua'
    filename: /Users/i.koptelov/IdeaProjects/graphql/test/space/nested_args.test.lua
    what: Lua
    namewhat: local
    name: run_common_queries
    src: '...lov/IdeaProjects/graphql/test/space/nested_args.test.lua'
  - line: 0
    source: '@/Users/i.koptelov/IdeaProjects/graphql/test/space/nested_args.test.lua'
    filename: /Users/i.koptelov/IdeaProjects/graphql/test/space/nested_args.test.lua
    what: main
    namewhat: 
    src: '...lov/IdeaProjects/graphql/test/space/nested_args.test.lua'
  line: 0
  expected: table
  got: nil
  ...
ok - upside
# failed subtest: 1
optional_require: no module rex_pcre2
2018-04-27 11:21:46.690 [92003] main/101/nested_args.test.lua C> Tarantool 1.9.0-61-gcd48321d3
2018-04-27 11:21:46.694 [92003] main/101/nested_args.test.lua C> log level 5
2018-04-27 11:21:46.694 [92003] main/101/nested_args.test.lua I> mapping 268435456 bytes for memtx tuple arena...
2018-04-27 11:21:46.694 [92003] main/101/nested_args.test.lua I> mapping 134217728 bytes for vinyl tuple arena...
2018-04-27 11:21:46.695 [92003] main/101/nested_args.test.lua I> initializing an empty data directory
2018-04-27 11:21:46.699 [92003] snapshot/101/main I> saving snapshot `./00000000000000000000.snap.inprogress'
2018-04-27 11:21:46.700 [92003] snapshot/101/main I> done
2018-04-27 11:21:46.701 [92003] main/101/nested_args.test.lua I> ready to accept requests
2018-04-27 11:21:46.701 [92003] main/104/checkpoint_daemon I> started
2018-04-27 11:21:46.701 [92003] main/104/checkpoint_daemon I> scheduled the next snapshot at Fri Apr 27 13:15:45 2018
2018-04-27 11:21:48.310 [92003] main/101/nested_args.test.lua I> ERROR: ...ts/graphql/test/space/../../graphql/accessor_general.lua:869: query execution timeout exceeded, use `timeout_ms` to increase it
2018-04-27 11:21:48.310 [92003] main/101/nested_args.test.lua I> stack traceback:
	.../IdeaProjects/graphql/test/space/../../graphql/utils.lua:15: in function <.../IdeaProjects/graphql/test/space/../../graphql/utils.lua:13>
	[C]: in function 'assert'
	...ts/graphql/test/space/../../graphql/accessor_general.lua:869: in function 'process_tuple'
	...ts/graphql/test/space/../../graphql/accessor_general.lua:1037: in function 'select'
	...s/graphql/test/space/../../graphql/tarantool_graphql.lua:539: in function 'defaultResolver'
	...ojects/graphql/test/space/../../graphql/core/execute.lua:110: in function 'fn'
	...aProjects/graphql/test/space/../../graphql/core/util.lua:5: in function <...aProjects/graphql/test/space/../../graphql/core/util.lua:3>
	[C]: in function 'xpcall'
	.../IdeaProjects/graphql/test/space/../../graphql/utils.lua:11: in function 'show_trace'
	...lov/IdeaProjects/graphql/test/space/nested_args.test.lua:100: in function 'run_common_queries'
	...lov/IdeaProjects/graphql/test/space/nested_args.test.lua:170: in main chunk
2018-04-27 11:21:48.324 [92003] main/101/nested_args.test.lua F> ...lov/IdeaProjects/graphql/test/space/nested_args.test.lua:173: check plan

[Totktonada]

Observed on pcre.test.lua too.