Specify minimum versions of peerDependencies for consistency with readme

Author: nickserv

README.md

@@ -5,7 +5,7 @@
 Webpack plugin that runs typescript type checker on a separate process.
 
 ## Installation
-This plugin requires minimum **webpack 2.3**, **typescript 2.1** and optionally **tslint 5.0**
+This plugin requires minimum **webpack 2.3**, **typescript 2.1** and optionally **tslint 4.0**
 ```sh
 npm install --save-dev fork-ts-checker-webpack-plugin
 ```

package.json

@@ -78,9 +78,9 @@
     "webpack": "^4.0.0"
   },
   "peerDependencies": {
-    "tslint": "^4.0.0 || ^5.0.0",
-    "typescript": "^2.1.0",
-    "webpack": "^2.3.0 || ^3.0.0 || ^4.0.0"
+    "tslint": ">= 4.0.0",
+    "typescript": ">= 2.1.0",
+    "webpack": ">= 2.3.0"
   },
   "dependencies": {
     "babel-code-frame": "^6.22.0",