set version to 2.0.3

Added tests for calculating/verification absolute and relative paths (#2

)

* Fixed build, fixed tests, fixed debug env, added test for relative and absolute paths

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Co-authored-by: Fabian Grutschus <[email protected]>

add unit tests

add verification and change output

- add parameters for verification, verbosity and such
- changed output to output "hash *file"
- add SHA256SUMS verification via -c FILE
- add visual studio solution
- changed argument parsing
- add exit codes for every success and failure
- rewrote documentation
- add version
-

rewrite with winapi