Fix integration test read volume dir error.
Merge pull request #1579 from ddysher/integration-fix

Fix integration test read volume dir error.
Ignore empty pod port spec.
Remove JSONBase reference from v1beta3/types.go
Merge pull request #1580 from ghodss/fix_v1beta3_jsonbase_error

Compilation error on HEAD: Remove JSONBase reference from v1beta3/types.go to prevent it
Merge pull request #1583 from ddysher/fix-#1550

Ignore empty pod port spec.