Remove CHANGELOG.md note regarding versioning. (#1704)

Since we’ve moved to independent versioning the statement about every package within this repository being at the same version is no longer true.  While we’ll need to improve our `CHANGELOG.md` story a bit to account for this, it’s best that we remove this statement to avoid confusing library consumers.

Author: abernix

CHANGELOG.md

@@ -1,7 +1,5 @@
 # Changelog
 
-All of the packages in the `apollo-server` repo are released with the same version numbers, so a new version of a particular package might not represent an actual change to that package. We generally try to mark changes that affect only one web server integration package with that package name, and don't specify package names for changes that affect most of the packages or which affect shared core packages.
-
 ### vNEXT
 
 - Allow an optional function to resolve the `rootValue`, passing the `DocumentNode` AST to determine the value. [PR #1555](https://github.com/apollographql/apollo-server/pull/1555)