Breaking: Make prettier a peerDependency (#1)

This allows the user to choose their version.

Author: lydell

README.md

@@ -16,6 +16,12 @@ Next, install `eslint-plugin-prettier`:
 $ npm install eslint-plugin-prettier --save-dev
 ```
 
+Finally, install `prettier`:
+
+```
+$ npm install prettier --save-dev
+```
+
 **Note:** If you installed ESLint globally (using the `-g` flag) then you must also install `eslint-plugin-prettier` globally.
 
 ## Usage

package.json

@@ -22,18 +22,19 @@
   },
   "homepage": "https://github.com/not-an-aardvark/eslint-plugin-prettier#readme",
   "dependencies": {
-    "prettier": "^0.11.0",
     "requireindex": "~1.1.0"
   },
   "peerDependencies": {
-    "eslint": "^3.14.1"
+    "eslint": "^3.14.1",
+    "prettier": ">= 0.11.0"
   },
   "devDependencies": {
     "eslint": "^3.14.1",
     "eslint-config-not-an-aardvark": "^2.0.0",
     "eslint-plugin-eslint-plugin": "^0.2.1",
     "eslint-plugin-node": "^3.0.5",
-    "mocha": "^3.1.2"
+    "mocha": "^3.1.2",
+    "prettier": ">= 0.11.0"
   },
   "engines": {
     "node": ">=4.0.0"