build.sbt includes com.hadoop.gplcompression which is GPLv3

[kortemik]

build.sbt includes com.hadoop.gplcompression which is GPLv3 therefore this project should be too to comply with the terms.

What is this PR for?
Change license to be compatible with license of com.hadoop.gplcompression:hadoop-lzo:jar:0.4.19
https://github.com/twitter/hadoop-lzo/blob/master/src/main/java/com/hadoop/compression/lzo/CChecksum.java#L4-L7

see https://www.gnu.org/licenses/quick-guide-gplv3.html

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}