disallow relative paths in ConanAPI constructor #325

Job	Run time
Determine Python versions	1s
OSX test suite / Setup and Cache Dependencies	1m 15s
Linux test suite / Build Linux container	8s
Windows test suite / Unit & Integration Tests (3.10)	17m 22s
Windows test suite / Functional Tests (3.10)	45m 47s
Linux test suite / Docker Runner Tests (3.10)	1m 54s
Linux test suite / Unit Tests (3.10)	1m 55s
Linux test suite / Integration Tests (3.10)	4m 36s
Linux test suite / Functional Tests (3.10)	5m 51s
OSX test suite / Unit Tests (3.10)	1m 9s
OSX test suite / Integration Tests (3.10)	2m 25s
OSX test suite / Functional Tests (3.10)	20m 24s
Deploy to TestPyPI	0s
Code coverage	0s
	1h 42m 47s

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