Update integration tests.

1. Use okhttp client transport for okhttp tests.
2. Utilize GrpcClient to construct channel according to the transport type.
3. Remove the unused middle layer abstract tests after above changes.

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Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=72732333
3 files changed
tree: f905047d1e946ef7b67b847bce803f9f166f8565
  1. core/
  2. stub/
  3. testing/
  4. LICENSE