Change: Use peerDependencies instead of dependencies

In the past we used dependencies in package.json which can blow up the bundle size a lot.
Expect this, it is also possible that the same package with 2 versions is part of the bundle.

From now on dependencies that are required to use ODS are added to the peerDependencies section in package.json.
Then the consuming application has to add the dependency on it's own and can decide which minor or bugfix version to use.

https://github.com/owncloud/owncloud-design-system/pull/1202
