Kythe verifier Import test uses hardcoded package

Fails with GHC 7.10:

```
export STACK_YAML=$(readlink -f stack-6.30.yaml)
stack install
cd kythe_verifier
./test.sh
```
```
Verifying: testdata/basic/ImportsRef.hs
Could not verify all goals. The furthest we reached was:
testdata/basic/ImportsRef.hs:5:6-5:89 @"Data.Set" ref/imports vname("containers-0.5.7.1:Data.Set", "", "", "", "haskell")
```

In the broader context, we might want to make verifier tests dependent on GHC version. Maybe fire up the tests with a light Haskell wrapper (instead shell script), where we can ifdef which tests we want to run. That way CI integrating those tests would also be easier (could move them into the ghc-kythe package).

cc @ivan444