Unpin astropy in integration tests

22 jobs for master in 1 minute and 46 seconds (queued for 1 second)
Name Stage Failure
failed
docs Test There has been a missing dependency failure
No job log
failed
test/coverage Test There has been a missing dependency failure
No job log
failed
tests/review Test There has been a missing dependency failure
No job log
failed
test/python3.7 Test There has been a missing dependency failure
No job log
failed
test/python3.8 Test There has been a missing dependency failure
No job log
failed
dependencies/python3.6 Dist There has been a missing dependency failure
No job log