test: skip master-replica tests if popen is not supported

Since version 2.4.1, Tarantool has the popen built-in module
that supports execution of external programs.
popen() uses in tests for creating replica instance.

Follows up #120

Author: 0x501D

t/200-master-replica.t

@@ -1,6 +1,7 @@
 #!/usr/bin/env tarantool
 
 local fio   = require('fio')
+local log   = require('log')
 local tnt   = require('t.tnt')
 local test  = require('tap').test('')
 local uuid  = require('uuid')
@@ -11,7 +12,13 @@ local session  = require('queue.abstract.queue_session')
 local queue_state = require('queue.abstract.queue_state')
 rawset(_G, 'queue', require('queue'))
 
--- Replica connection handler
+local qc = require('queue.compat')
+if not qc.check_version({2, 4, 1}) then
+    log.info('Tests skipped, tarantool version < 2.4.1')
+    return
+end
+
+-- Replica connection handler.
 local conn = {}
 
 test:plan(5)

t/tnt/init.lua

@@ -3,7 +3,6 @@ local log   = require('log')
 local yaml  = require('yaml')
 local errno = require('errno')
 local fiber  = require('fiber')
-local popen  = require('popen')
 local netbox = require('net.box')
 
 local dir     = os.getenv('QUEUE_TMP')
@@ -55,6 +54,13 @@ end
 
 -- Creates master and replica setup for queue states switching tests.
 local function tnt_cluster_prepare(cfg_args)
+    -- Since version 2.4.1, Tarantool has the popen built-in module
+    -- that supports execution of external programs.
+    if not qc.check_version({2, 4, 1}) then
+        error('this test requires tarantool >= 2.4.1')
+        return false
+    end
+
     -- Prepare master.
     cfg_args = cfg_args or {}
     local files = fio.glob(fio.pathjoin(dir, '*'))
@@ -111,7 +117,7 @@ local function tnt_cluster_prepare(cfg_args)
         '}'
     }
 
-    replica = popen.new(cmd_replica, {
+    replica = require('popen').new(cmd_replica, {
         stdin = 'devnull',
         stdout = 'devnull',
         stderr = 'devnull',