feature symfony#4 Add EkinoNewrelicBundle (GromNaN)

This PR was squashed before being merged into the master branch (closes symfony#4).

Discussion
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Add EkinoNewrelicBundle

* Is it possible to add conditional configuration when an other bundle is installed? This bundle has interactions with [SonataBlockBundle](https://github.com/ekino/EkinoNewRelicBundle#integration-with-sonatablockbundle).
* Configuration could be made interactive with questions like "What transaction naming do you want to use?" or "Are you using Symfony HTTP Cache?"

Commits
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9f04f15 Add EkinoNewrelicBundle

Author: fabpot

ekino/newrelic-bundle/1.3/etc/packages/prod/ekino_new_relic.yaml

@@ -0,0 +1,4 @@
+ekino_new_relic:
+    enabled: true
+    api_key: "%env(NEWRELIC_API_KEY)%"
+    log_exceptions: true

ekino/newrelic-bundle/1.3/manifest.json

@@ -0,0 +1,12 @@
+{
+    "bundles": {
+        "Ekino\\Bundle\\NewRelicBundle\\NewRelicBundle": ["prod"]
+    },
+    "copy-from-recipe": {
+        "etc/": "%ETC_DIR%/"
+    },
+    "env": {
+        "#1": "Get the REST API key of your NewRelic Account on https://docs.newrelic.com/docs/apis/rest-api-v2/requirements/api-keys",
+        "NEWRELIC_API_KEY": "FIXME"
+    }
+}