Set default SALT_VERSION: 2017.7.7 for test-salt-formula-{{name}}-latest

  * This option to be passed into ./run_tests.sh syntax checkedю
  * This is WA for[1]: future solution should be re-implemented to relay on
    binary packages, even in tests.

[1] https://github.com/saltstack/salt/issues/46929
Related-Bug: PROD-22323 (PROD:22323)

Change-Id: Ibcc595e956b43481ce6897fc8c10d2b0b0f602b3
1 file changed