YETUS-1237. add release 0.15.0

- list in releases
- remove 0.12.0, add 0.15.0 to docs and downloads

Author: aw-was-here

asf-site-src/data/htaccess.yml

@@ -15,6 +15,6 @@
 ---
 redirect:
   /latest.tgz: >
-    https://www.apache.org/dyn/closer.cgi?action=download&filename=yetus/0.14.1/apache-yetus-0.14.1-bin.tar.gz
+    https://www.apache.org/dyn/closer.cgi?action=download&filename=yetus/0.15.0/apache-yetus-0.15.0-bin.tar.gz
   /latest.tgz.asc: >
-    https://downloads.apache.org/yetus/0.14.1/apache-yetus-0.14.1-bin.tar.gz.asc
+    https://downloads.apache.org/yetus/0.15.0/apache-yetus-0.15.0-bin.tar.gz.asc

asf-site-src/data/versions.yml

@@ -16,6 +16,6 @@
 # under the License.
 ---
 releases:
-  - '0.12.0'
   - '0.13.0'
   - '0.14.1'
+  - '0.15.0'