Update ELK images

elasticsearch:
- https://github.com/docker-library/elasticsearch/commit/95f585f: Update to 7.9.0
- https://github.com/docker-library/elasticsearch/commit/d8dcb64: Update to 6.8.12
- https://github.com/docker-library/elasticsearch/commit/0d9640d: Update generated README

logstash:
- https://github.com/docker-library/logstash/commit/4991fcd: Update to 7.9.0
- https://github.com/docker-library/logstash/commit/68d016f: Update to 6.8.12
- https://github.com/docker-library/logstash/commit/0bf96bd: Update generated README

kibana:
- https://github.com/docker-library/kibana/commit/cee1991: Update to 7.9.0
- https://github.com/docker-library/kibana/commit/0ebcdf7: Update to 6.8.12

library/elasticsearch

@@ -4,12 +4,12 @@ Maintainers: Tianon Gravi <[email protected]> (@tianon),
              Joseph Ferguson <[email protected]> (@yosifkit)
 GitRepo: https://github.com/docker-library/elasticsearch.git
 
-Tags: 7.8.1
+Tags: 7.9.0
 Architectures: amd64, arm64v8
-GitCommit: 5f77876bff63a699806e21e7ce3b23f264caf86e
+GitCommit: 95f585fbba9baa25ac3acea6ae5fb938f09a7f67
 Directory: 7
 
-Tags: 6.8.11
+Tags: 6.8.12
 Architectures: amd64
-GitCommit: a307d268b244992f796b73ea51d9e25db0f8acb1
+GitCommit: d8dcb6409e70fbd4749ffb06b15d32c8c1b0824a
 Directory: 6

library/kibana

@@ -4,10 +4,10 @@ Maintainers: Tianon Gravi <[email protected]> (@tianon),
              Joseph Ferguson <[email protected]> (@yosifkit)
 GitRepo: https://github.com/docker-library/kibana.git
 
-Tags: 7.8.1
-GitCommit: b922235278db729dd1e865c4df02637fd589c541
+Tags: 7.9.0
+GitCommit: cee19912df82209e21583b7db91e0fc4e0a786db
 Directory: 7
 
-Tags: 6.8.11
-GitCommit: 6721854df0e23db4bc4ca6ce2d8efa33738ad934
+Tags: 6.8.12
+GitCommit: 0ebcdf78ff61cd1f293732350c4654365363b148
 Directory: 6

library/logstash

@@ -4,10 +4,10 @@ Maintainers: Tianon Gravi <[email protected]> (@tianon),
              Joseph Ferguson <[email protected]> (@yosifkit)
 GitRepo: https://github.com/docker-library/logstash.git
 
-Tags: 7.8.1
-GitCommit: ea72914ddda62638a5afac3d3729d36143e1d4d1
+Tags: 7.9.0
+GitCommit: 4991fcd34f4ac0925c57f785148c7368abaadc79
 Directory: 7
 
-Tags: 6.8.11
-GitCommit: 2a03356e097a604c50ade39ec5b07c15b6ed07b8
+Tags: 6.8.12
+GitCommit: 68d016fed30f1a646ad37a46b007b2e4adaeda88
 Directory: 6