minor #19245 Fix some lowest deps (nicolas-grekas)

This PR was merged into the 2.8 branch.

Discussion
----------

Fix some lowest deps

| Q             | A
| ------------- | ---
| Branch?       | 2.8
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | -
| License       | MIT
| Doc PR        | -

A 2.8-only issue

Commits
-------

aa0e8bd Fix some lowest deps

src/Symfony/Bundle/FrameworkBundle/composer.json

@@ -24,7 +24,7 @@
         "symfony/event-dispatcher": "~2.8|~3.0.0",
         "symfony/finder": "~2.0,>=2.0.5|~3.0.0",
         "symfony/http-foundation": "~2.7",
-        "symfony/http-kernel": "~2.7.15|~2.8.8",
+        "symfony/http-kernel": "~2.8.8",
         "symfony/polyfill-mbstring": "~1.0",
         "symfony/filesystem": "~2.3|~3.0.0",
         "symfony/routing": "~2.8|~3.0.0",

src/Symfony/Component/HttpKernel/composer.json

@@ -18,7 +18,7 @@
     "require": {
         "php": ">=5.3.9",
         "symfony/event-dispatcher": "~2.6,>=2.6.7|~3.0.0",
-        "symfony/http-foundation": "~2.8.8|~3.0.8",
+        "symfony/http-foundation": "~2.7.15|~2.8.8|~3.0.8",
         "symfony/debug": "~2.6,>=2.6.2",
         "psr/log": "~1.0"
     },