7.2.1 release notes (#1318)

Author: jakelandis

docs/src/reference/asciidoc/appendix/release-notes/7.2.1.adoc

@@ -0,0 +1,5 @@
+[[eshadoop-7.2.1]]
+== Elasticsearch for Apache Hadoop version 7.2.1
+July 16, 2019
+
+ES-Hadoop 7.2.1 is a version compatibility release, tested specifically against Elasticsearch 7.2.1.

docs/src/reference/asciidoc/appendix/release.adoc

@@ -8,6 +8,7 @@ This section summarizes the changes in each release.
 [float]
 [[release-notes-7]]
 ===== 7.x
+* <<eshadoop-7.2.1>>
 * <<eshadoop-7.2.0>>
 * <<eshadoop-7.1.1>>
 * <<eshadoop-7.1.0>>
@@ -67,6 +68,7 @@ http://github.com/elastic/elasticsearch-hadoop/issues/XXX[#XXX]
 
 ////////////////////////
 
+include::release-notes/7.2.1.adoc[]
 include::release-notes/7.2.0.adoc[]
 include::release-notes/7.1.1.adoc[]
 include::release-notes/7.1.0.adoc[]