* add placeholder to spec
* add output_directory to pipeline
* respect uri placeholder in file outputs
* wip: add data passing rewriting logic to respect the uri semantics
* merge input_uri and paths when instantiating ContainerOp
* fix
* fix workflow rewriting
* Add topology rewriting
* add a test case, and various fixes
* make the test case more complex
* Fix the case when working with OpsGroup
* Fix test case
* fix resolving test
* fix redundant cmd lines
* fix redundant cmd lines
* resolve comments
* fix file outputs
* resolve comments
* copy file outputs instead of modifying inplace.
Removed path resolving in two tests.
The `.resolve()` should be harmless, but I've seen these tests fail to work in some unusual strict hermetic systems. The test code file path was resolving to a tree which was different from the parent of the file, so the test could not find the test data.
Jiaxiao Zheng
Chen Sun
Alexey Volkov