Enable parallel tests by default for some suites

.travis.mk

rpm/tarantool.spec

test-run

test/app-tap/snapshot.test.lua

test/app-tap/suite.ini

test/app/suite.ini

test/box-py/suite.ini

test/box-tap/suite.ini

test/box/suite.ini

test/engine/suite.ini

test/engine_long/suite.ini

test/long_run-py/suite.ini

test/replication-py/suite.ini

test/replication/suite.ini

test/unit/suite.ini

test/vinyl/suite.ini

test/wal_off/suite.ini

test/xlog-py/suite.ini

test/xlog/suite.ini