[BEAM-3139] Update dataflow.version on the beam root pom.xml

[ajamato]

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Update dataflow.version on the beam root pom.xml to v1b3-rev218-1.22.0

[ajamato]

R: @kennknowles

[ajamato]

retest this please

[kennknowles]

run Dataflow ValidatesRunner

[kennknowles]

LGTM

[kennknowles]

Can you squash the commits to make it really easy for me to merge it?

[ajamato]

Done, is that the proper way to squash them?

[kennknowles]

Looks good to me. Any set of commits is OK as long as they are each something that makes sense on their own, and is legible in the history. Also, pragmatically, the easiest unit of rollback in addition to the atomic unit of history/blame.