Update to version 1.9.0
Bump version information for 1.9.0 release
Signed-off-by: David Brown <david.brown@linaro.org>
diff --git a/docs/release-notes.md b/docs/release-notes.md
index 3be209d..43af557 100644
--- a/docs/release-notes.md
+++ b/docs/release-notes.md
@@ -31,6 +31,7 @@
- Remove zephyr example test running in shell. The Go version is
primary and much more featureful.
- imgtool: make `--max-align` default reasonable in most cases.
+- Implement the mcumgr echo command in serial boot mode
### Security fixes