bump postgres versions #292

Job	Run time
push-test-images-for-release	0s
prepare_pgversion_matrix	4s
push-test-images-for-dev (citusupgradetester)	3m 45s
push-test-images-for-dev (pgupgradetester)	2m 38s
push-test-images-for-dev (stylechecker)	2m 21s
push-test-images-for-dev (extbuilder, 14.12)	1m 18s
push-test-images-for-dev (extbuilder, 15.7)	1m 26s
push-test-images-for-dev (extbuilder, 16.3)	1m 26s
push-test-images-for-dev (exttester, 14.12)	3m 23s
push-test-images-for-dev (exttester, 15.7)	3m 12s
push-test-images-for-dev (exttester, 16.3)	3m 18s
push-test-images-for-dev (failtester, 14.12)	1m 51s
push-test-images-for-dev (failtester, 15.7)	2m 21s
push-test-images-for-dev (failtester, 16.3)	2m 16s
	29m 19s

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