Prepare v1.15.0 release (#728)

* Prepare v1.15.0 release * Fix changelog link

Author: nick-benoit

Makefile

@@ -1,5 +1,5 @@
 SHELL := /bin/bash
-export VERSION ?= v1.14.4
+export VERSION ?= v1.15.0
 export GO111MODULE ?= on
 export GOBIN = $(shell pwd)/bin
 BINARY := ecctl

notes/v1.14.4.md

@@ -0,0 +1,21 @@
+v1.15.0
+
+# Changelog
+
+Download the release binaries:
+
+<https://download.elastic.co/downloads/ecctl/1.15.0/ecctl_1.15.0_darwin_amd64.tar.gz>
+<https://download.elastic.co/downloads/ecctl/1.15.0/ecctl_1.15.0_darwin_arm64.tar.gz>
+<https://download.elastic.co/downloads/ecctl/1.15.0/ecctl_1.15.0_linux_32-bit.deb>
+<https://download.elastic.co/downloads/ecctl/1.15.0/ecctl_1.15.0_linux_32-bit.rpm>
+<https://download.elastic.co/downloads/ecctl/1.15.0/ecctl_1.15.0_linux_386.tar.gz>
+<https://download.elastic.co/downloads/ecctl/1.15.0/ecctl_1.15.0_linux_64-bit.deb>
+<https://download.elastic.co/downloads/ecctl/1.15.0/ecctl_1.15.0_linux_64-bit.rpm>
+<https://download.elastic.co/downloads/ecctl/1.15.0/ecctl_1.15.0_linux_amd64.tar.gz>
+<https://download.elastic.co/downloads/ecctl/1.15.0/ecctl_1.15.0_linux_arm64.tar.gz>
+
+Checksums are at [ecctl_1.15.0_checksums.txt](https://download.elastic.co/downloads/ecctl/1.15.0/ecctl_1.15.0_checksums.txt).
+
+## Release notes
+
+<https://www.elastic.co/guide/en/ecctl/1.15/ecctl-release-notes-v1.15.0.html>