Make npm compile script work on windows. (#62)

Make npm run compile script work on windows.
Move dependencies to rimraf, mkdirp and babel to dev-dependencies

package.json

@@ -4,7 +4,7 @@
   "description": "Image Module for docxtemplater v1.0",
   "main": "js/index.js",
   "scripts": {
-    "compile": "rm js -rf ; mkdir -p js; babel es6 --out-dir js",
+    "compile": "rimraf js && mkdirp js && babel es6 --out-dir js",
     "prepublish": "npm run compile",
     "test:compiled": "mocha js/test.js",
     "test:es6": "mocha es6/test.js",
@@ -12,13 +12,15 @@
     "test": "npm run compile && npm run test:compiled"
   },
   "devDependencies": {
-    "babel-cli": "^6.7.5",
     "babel-eslint": "^6.0.2",
     "babel-preset-es2015": "^6.3.13",
     "chai": "^3.4.1",
     "docxtemplater": "^2.1.0",
     "eslint": "^2.7.0",
-    "mocha": "^2.4.5"
+    "mocha": "^2.4.5",
+    "mkdirp": "^0.5.1",
+    "babel-cli": "^6.11.4",
+    "rimraf": "^2.5.3"
   },
   "repository": {
     "type": "git",