Finish the CouchDB test matrix

Let's move the test documents into a separate file (`./tests/fixtures/documents.txt`) with one document per line and make a loop like this instead:

```bash
while read document
  curl -X POST \
       -H "Content-Type: application/json" \
       -d $document
       localhost:5984/source
done < $TRAVIS_BUILD_DIR/tests/fixtures/documents.txt
```

Then we can do this at the end:

```bash
DOC_COUNT=$(wc -l $TRAVIS_BUILD_DIR/tests/fixtures/documents.txt)
exit test 1 -eq $(egrep -c "(\"total_rows\"\:$DOC_COUNT)" /tmp/all_docs.txt)
```

I think this will be cleaner. Then it's also easier to add new documents to test with.