convert CRC16 to Scala

[zaneli]

Maybe fix #225 ?

> java -version
openjdk version "11.0.1" 2018-10-16
OpenJDK Runtime Environment 18.9 (build 11.0.1+13)
OpenJDK 64-Bit Server VM 18.9 (build 11.0.1+13, mixed mode)

> sbt ++2.13.0 publishLocal

> unzip rediscala_2.13-1.9.0.jar

> javap -verbose redis/util/CRC16.class | grep version
  minor version: 0
  major version: 52

[coveralls]

Coverage increased (+0.3%) to 90.776% when pulling 22ba50b on zaneli:refactor/crc16-scala into 5600b00 on etaty:master.

[bluesheeptoken]

@etaty Hello, I am mentioning you here to hopefully draw your attention.

Is there any interest in merging this PR? This would be helpful as I do not think we need any features from JDK11 (am I right ?).

Another solution could be to republish a version 1.10 using Java 8? (I have not tested it myself though, I just read some comments on the linked issue)

I am here to give you a hand if any help is needed

Edit: I also submitted a PR to target java8