Update Symfony component requirements (#209)

- Update to allow 3.0+ Symfony components for support of Drupal 8.4+
- Update project type
- Remove composer.lock

.gitignore

@@ -2,6 +2,7 @@
 /.rules
 
 # Composer
+composer.lock
 /vendor
 /bin/phpunit
 /bin/jsonlint

composer.json

@@ -3,7 +3,7 @@
     "description": "Drupal Console Core",
     "keywords": ["Drupal", "Console", "Development", "Symfony"],
     "homepage": "http://drupalconsole.com/",
-    "type": "project",
+    "type": "library",
     "license": "GPL-2.0+",
     "authors": [
         {
@@ -40,16 +40,16 @@
         "dflydev/dot-access-configuration": "^1.0",
         "drupal/console-en": "1.0.0-rc25",
         "stecman/symfony-console-completion": "~0.7",
-        "symfony/config": "~2.8",
-        "symfony/console": "~2.8",
-        "symfony/debug": "~2.8",
-        "symfony/dependency-injection": "~2.8",
-        "symfony/event-dispatcher": "~2.8",
-        "symfony/filesystem": "~2.8",
-        "symfony/finder": "~2.8",
-        "symfony/process": "~2.8",
-        "symfony/translation": "~2.8",
-        "symfony/yaml": "~2.8",
+        "symfony/config": "~2.8|~3.0",
+        "symfony/console": "~2.8|~3.0",
+        "symfony/debug": "~2.8|~3.0",
+        "symfony/dependency-injection": "~2.8|~3.0",
+        "symfony/event-dispatcher": "~2.8|~3.0",
+        "symfony/filesystem": "~2.8|~3.0",
+        "symfony/finder": "~2.8|~3.0",
+        "symfony/process": "~2.8|~3.0",
+        "symfony/translation": "~2.8|~3.0",
+        "symfony/yaml": "~2.8|~3.0",
         "twig/twig": "^1.23.1",
         "webflo/drupal-finder": "^0.3.0",
         "webmozart/path-util": "^2.3"