Remove stale roadmap items (#2605)

Author: paulb777

ROADMAP.md

@@ -4,21 +4,6 @@
 
 The Firebase team plans to open source more of Firebase components.
 
-## Continuous Integration
-
-* [Stabilize Travis](https://github.com/firebase/firebase-ios-sdk/issues/102)
-* [Verify Objective-C style guide compliance](https://github.com/firebase/firebase-ios-sdk/issues/103)
-
-## Samples and Integration Tests
-
-Add more samples to better demonstrate the capabilities of Firebase and help
-developers onboard.
-
-## Xcode 9 Workflow
-
-[Ensure Firebase open source development works well with Xcode 9's git and
-GitHub features](https://github.com/firebase/firebase-ios-sdk/issues/101).
-
 ## Other
 
 Check out the [issue list](https://github.com/firebase/firebase-ios-sdk/issues)