Tests

Remove readline from test_highline #42

Job	Run time
test (ubuntu-latest, head)	30s
test (ubuntu-latest, 3.3)	19s
test (ubuntu-latest, 3.2)	27s
test (ubuntu-latest, 3.1)	28s
test (ubuntu-latest, 3.0)	26s
test (ubuntu-latest, jruby)	1m 5s
test (ubuntu-latest, jruby-head)	1m 7s
test (ubuntu-latest, truffleruby)	44s
test (ubuntu-latest, truffleruby-head)	50s
test (ubuntu-latest, truffleruby+graalvm)	2m 59s
test (windows-latest, head)	1m 51s
test (windows-latest, 3.3)	2m 30s
test (windows-latest, mingw)	1m 19s
test (windows-latest, mswin)	2m 3s
test (windows-latest, ucrt)	1m 23s
test (macos-latest, head)	27s
test (macos-latest, 3.3)	21s
	18m 49s

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