Quote ETag

[adhesivee]

Formal way of using ETag is by quoting them: https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/ETag#etag_value

[tipsy]

It seems to have some effect on existing tests:

Error:  Tests run: 30, Failures: 0, Errors: 1, Skipped: 0, Time elapsed: 0.579 s <<< FAILURE! -- in io.javalin.TestCompression
Error:  io.javalin.TestCompression.dynamic handler responds with 304 when ETag is set -- Time elapsed: 0.016 s <<< ERROR!
java.lang.RuntimeException: 
java.lang.Exception: Assertion error: 
expected: 304
 but was: 200

[tipsy]

Do you want to try to get this fixed @adhesivee ?