bugfix #156 Explicitly require "twig/twig" since it is used by the Twig ticket extensions (phansys)

This PR was merged into the master branch.

Discussion
----------

|Q            |A     |
|---          |---   |
|Branch       |master|
|Bug fix?     |yes   |
|New feature? |no    |
|BC breaks?   |no    |
|Deprecations?|no    |
|Tests pass?  |yes   |
|Fixed tickets|n/a   |
|License      |MIT   |
|Doc PR       |n/a   |

This partially reverts #146.

Commits
-------

094706c Explicitly require "twig/twig" since it is used by the Twig ticket extensions

Author: phansys

composer.json

@@ -42,7 +42,8 @@
         "symfony/translation": "^2.8 || ^3.0 || ^4.0",
         "symfony/twig-bundle": "^2.8 || ^3.0 || ^4.0",
         "symfony/validator": "^2.8 || ^3.0 || ^4.0",
-        "symfony/yaml": "^2.8 || ^3.0 || ^4.0"
+        "symfony/yaml": "^2.8 || ^3.0 || ^4.0",
+        "twig/twig": "^1.34 || ^2.0"
     },
     "require-dev": {
         "ext-pdo_sqlite": "*",
@@ -51,9 +52,6 @@
         "symfony/phpunit-bridge": "^3.2 || ^4.0",
         "symfony/security": "^2.8 || ^3.0 || ^4.0"
     },
-    "conflict": {
-        "twig/twig": "<1.34"
-    },
     "suggest": {
         "friendsofsymfony/user-bundle": "In order to ease user management",
         "vich/uploader-bundle": "Allow attaching files to ticket messages"