Update Makefile and CHANGELOG for v1.5.1

CHANGELOG.md

 # Release Notes
 
+## Version 1.5.1 - 2019-10-29
+
+* Set Docker open-files limit ( 'ulimit -n') to be consistent with other runtimes [#5761](https://github.com/kubernetes/minikube/pull/5761)
+* Use fixed uid/gid for the default user account [#5767](https://github.com/kubernetes/minikube/pull/5767)
+* Set --wait=false to default but still wait for apiserver [#5757](https://github.com/kubernetes/minikube/pull/5757)
+* kubelet: Pass --config to use kubeadm generated configuration [#5697](https://github.com/kubernetes/minikube/pull/5697)
+* Refactor to remove opening browser and just return url(s) [#5718](https://github.com/kubernetes/minikube/pull/5718)
+
+Huge thank you for this release towards our contributors:
+
+- Anders F Björklund
+- Medya Ghazizadeh
+- Nanik T
+- Priya Wadhwa
+- Sharif Elgamal
+- Thomas Strömberg
+
 ## Version 1.5.0 - 2019-10-25
 
 * Default to best-available local hypervisor rather than VirtualBox [#5700](https://github.com/kubernetes/minikube/pull/5700)

Makefile

@@ -15,12 +15,12 @@
 # Bump these on release - and please check ISO_VERSION for correctness.
 VERSION_MAJOR ?= 1
 VERSION_MINOR ?= 5
-VERSION_BUILD ?= 0
+VERSION_BUILD ?= 1
 RAW_VERSION=$(VERSION_MAJOR).$(VERSION_MINOR).${VERSION_BUILD}
 VERSION ?= v$(RAW_VERSION)
 
 # Default to .0 for higher cache hit rates, as build increments typically don't require new ISO versions
-ISO_VERSION ?= v$(VERSION_MAJOR).$(VERSION_MINOR).0
+ISO_VERSION ?= v$(VERSION_MAJOR).$(VERSION_MINOR).$(VERSION_BUILD)
 # Dashes are valid in semver, but not Linux packaging. Use ~ to delimit alpha/beta
 DEB_VERSION ?= $(subst -,~,$(RAW_VERSION))
 RPM_VERSION ?= $(DEB_VERSION)