[BEAM-1518] support deflate file IO

[nevillelyh]

Be sure to do all of the following to help us incorporate your contribution
quickly and easily:

• Make sure the PR title is formatted like:
  [BEAM-<Jira issue #>] Description of pull request
• Make sure tests pass via mvn clean verify. (Even better, enable
  Travis-CI on your fork and ensure the whole test matrix passes).
• Replace <Jira issue #> in the title with the actual Jira issue
  number, if there is one.
• If this contribution is large, please file an Apache
  Individual Contributor License Agreement.

[coveralls]

Coverage decreased (-0.02%) to 69.153% when pulling 50da3c3 on nevillelyh:neville/BEAM-1518 into 5d6dafa on apache:master.

[asfbot]

Refer to this link for build results (access rights to CI server needed):
https://builds.apache.org/job/beam_PreCommit_Java_MavenInstall/7636/

Failed Tests: 1

beam_PreCommit_Java_MavenInstall/org.apache.beam:beam-runners-flink_2.10: 1

• org.apache.beam.runners.flink.streaming.GroupByNullKeyTest.testJob

--none--

[nevillelyh]

@dhalperi FYI

[dhalperi]

retest this please

this is a command to jenkins that rules out flakes

[coveralls]

Coverage increased (+0.1%) to 69.304% when pulling 50da3c3 on nevillelyh:neville/BEAM-1518 into 5d6dafa on apache:master.

[asfbot]

Refer to this link for build results (access rights to CI server needed):
https://builds.apache.org/job/beam_PreCommit_Java_MavenInstall/7889/

Failed Tests: 1

beam_PreCommit_Java_MavenInstall/org.apache.beam:beam-runners-flink_2.10: 1

• org.apache.beam.runners.flink.streaming.GroupByNullKeyTest.testJob

--none--

[coveralls]

Coverage increased (+0.1%) to 69.317% when pulling 50da3c3 on nevillelyh:neville/BEAM-1518 into 5d6dafa on apache:master.

[dhalperi]

Thanks Neville! Looks great!

[asfbot]

Refer to this link for build results (access rights to CI server needed):
https://builds.apache.org/job/beam_PreCommit_Java_MavenInstall/7890/

Failed Tests: 1

beam_PreCommit_Java_MavenInstall/org.apache.beam:beam-runners-flink_2.10: 1

• org.apache.beam.runners.flink.streaming.GroupByNullKeyTest.testJob

--none--