chore(package): update last-release-npm to 1.2.1

You can now map dist-tags onto "fallbackTags". E.g. if you want a
development channel like "next" and no version is currently published as "next"
semantic-release could fallback to "latest" to determine the new "next" version.
You can specify your mappings by adding "fallbackTags" to your
`package.json`'s "release" field.

README.md

@@ -1,10 +1,10 @@
 # semantic-release
 
-[![Build Status](https://travis-ci.org/semantic-release/semantic-release.svg?branch=next)](https://travis-ci.org/semantic-release/semantic-release)
-[![Coverage Status](https://coveralls.io/repos/semantic-release/semantic-release/badge.svg?branch=next&service=github)](https://coveralls.io/github/semantic-release/semantic-release?branch=next)
+[![Build Status](https://travis-ci.org/semantic-release/semantic-release.svg?branch=master)](https://travis-ci.org/semantic-release/semantic-release)
+[![Coverage Status](https://coveralls.io/repos/semantic-release/semantic-release/badge.svg?branch=master&service=github)](https://coveralls.io/github/semantic-release/semantic-release?branch=master)
 
-[![Dependency Status](https://david-dm.org/semantic-release/semantic-release/next.svg)](https://david-dm.org/semantic-release/semantic-release/next)
-[![devDependency Status](https://david-dm.org/semantic-release/semantic-release/next/dev-status.svg)](https://david-dm.org/semantic-release/semantic-release/next#info=devDependencies)
+[![Dependency Status](https://david-dm.org/semantic-release/semantic-release/master.svg)](https://david-dm.org/semantic-release/semantic-release/master)
+[![devDependency Status](https://david-dm.org/semantic-release/semantic-release/master/dev-status.svg)](https://david-dm.org/semantic-release/semantic-release/master#info=devDependencies)
 
 [![Join the chat at https://gitter.im/semantic-release/semantic-release](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/semantic-release/semantic-release?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
 [![semantic-release](https://img.shields.io/badge/%20%20%F0%9F%93%A6%F0%9F%9A%80-semantic--release-e10079.svg)](https://github.com/semantic-release/semantic-release)

package.json

@@ -24,7 +24,7 @@
     "@semantic-release/commit-analyzer": "^2.0.0",
     "@semantic-release/condition-travis": "^4.0.0",
     "@semantic-release/error": "^1.0.0",
-    "@semantic-release/last-release-npm": "^1.1.1",
+    "@semantic-release/last-release-npm": "^1.2.1",
     "@semantic-release/release-notes-generator": "^2.0.0",
     "git-head": "^1.2.1",
     "github": "^0.2.4",
@@ -66,12 +66,6 @@
   ],
   "license": "MIT",
   "main": "dist/index.js",
-  "publishConfig": {
-    "tag": "next"
-  },
-  "release": {
-    "branch": "next"
-  },
   "repository": {
     "type": "git",
     "url": "git+https://github.com/semantic-release/semantic-release.git"