Update dependencies

Author: Andrés Correa Casablanca

composer.json

@@ -5,11 +5,11 @@
     "license": "MIT",
     "require": {
         "php": ">=7.0",
-        "symfony/console": "~3.0",
-        "seld/cli-prompt": "~1.0"
+        "symfony/console": "^3.0",
+        "seld/cli-prompt": "^1.0"
     },
     "require-dev": {
-        "phpunit/phpunit": "^4.8|^5.2"
+        "phpunit/phpunit": "^6.1"
     },
     "autoload": {
         "psr-4": { "Litipk\\JupyterPhpInstaller\\": "src/"}