Since we don't want to add too many dependencies for now, use our own
small hexdump lib `hexhex` instead of `hexyl`.
Reviewed-on: #18
Co-authored-by: ddidderr <ddidderr@paul.network>
Co-committed-by: ddidderr <ddidderr@paul.network>
* implemented 3 tests
* valid opcodes
* invalid opcodes
* header too short
* fixed byteorder and bit shifting for flags
* added hexdump for main function for testing purposes
