Add 1.2 changelog with notable features and update kubernetes required

version to 1.15

CHANGELOG-1.2.md

@@ -0,0 +1,12 @@
+# Changelog since v1.1.0
+
+## New Features
+
+- Adds CSI Migration support for Azure Disk/File, fixes for backward compatible AccessModes for GCE PD. ([#156](https://github.com/kubernetes-csi/external-attacher/pull/156), [@davidz627](https://github.com/davidz627))
+- Support attachment of inline volumes migrated to CSI ([#154](https://github.com/kubernetes-csi/external-attacher/pull/154), [@ddebroy](https://github.com/ddebroy))
+- Adds --retry-interval-max and --retry-interval-start to the csi-attacher parameters to allow users to limit the exponential backoff retry time for requests. ([#141](https://github.com/kubernetes-csi/external-attacher/pull/141), [@barp](https://github.com/barp))
+
+
+## Bug Fixes
+
+- The default leader election type will be `configmaps` if not specified in the command line ([#144](https://github.com/kubernetes-csi/external-attacher/pull/144), [@mlmhl](https://github.com/mlmhl))

README.md

@@ -21,7 +21,7 @@ This information reflects the head of this branch.
 
 | Compatible with CSI Version                                                                | Container Image             | Min K8s Version |
 | ------------------------------------------------------------------------------------------ | ----------------------------| --------------- |
-| [CSI Spec v1.0.0](https://github.com/container-storage-interface/spec/releases/tag/v1.0.0) | quay.io/k8scsi/csi-attacher | 1.14            |
+| [CSI Spec v1.0.0](https://github.com/container-storage-interface/spec/releases/tag/v1.0.0) | quay.io/k8scsi/csi-attacher | 1.15            |
 
 ## Feature Status