Add npm run push-tag, to push a tag with the current package.json version

Author: Tehnix

package.json

@@ -204,7 +204,8 @@
         "postinstall": "node ./node_modules/vscode/bin/install",
         "test": "npm run compile && node ./node_modules/vscode/bin/test",
         "tslint": "tslint -p tsconfig.json -c tslint.json --format stylish 'src/**/*.ts'",
-        "tslint-fix": "tslint --fix -p tsconfig.json  -c tslint.json --format stylish 'src/**/*.ts'"
+        "tslint-fix": "tslint --fix -p tsconfig.json  -c tslint.json --format stylish 'src/**/*.ts'",
+        "push-tag": "git tag -a $npm_package_version -m \"Version $npm_package_version\" && git push origin $npm_package_version"
     },
     "devDependencies": {
         "@types/mocha": "^2.2.46",