v1.4.0

[NEW] support empty response body when only have status code (#163)
[NEW] add support cross package (#171)
[NEW] support type definitions not found under the search directory (#179)
[NEW] support custom primitive types (#198)

[FIX] always diff in testdata (#168)
[FIX] fix invalid response type: array of strings (#173)
[FIX] fix to address referencing types in external, vendored pkgs #188 (#189)