update changelogs for 1.15.0 release (#93)

Author: dgrove-oss

core/php7.2Action/CHANGELOG.md

@@ -17,7 +17,7 @@
 #
 -->
 
-## Next release
+## Apache 1.15.0
  - Update version of PHP to 7.2.33
 
 ## Apache 1.14.0

core/php7.3Action/CHANGELOG.md

@@ -16,8 +16,9 @@
 # limitations under the License.
 #
 -->
-## Next release
- - Update version of PHP to 7.3.22
+## Apache 1.15.0
+  - Update version of PHP to 7.3.22
+  - Use golang 1.15 and openwhisk-runtime-go 1.16.0 to build proxy
 
 ## Apache 1.14.0
 Changes:

core/php7.4Action/CHANGELOG.md

@@ -17,8 +17,9 @@
 #
 -->
 
-## Next release
- - Update version of PHP to 7.4.10
+## Apache 1.15.0
+  - Update version of PHP to 7.4.10
+  - Use golang 1.15 and openwhisk-runtime-go 1.16.0 to build proxy
 
 ## Apache 1.14.0
 Initial release