Test download endpoints

[jvscholz]

The following endpoints still require testing:

• [x] GET <URI>/sbol OR GET <URI>

• [x] GET <URI>/sbolnr

• [ ] GET <URI>/metadata

• [ ] GET <URI>/gb

• [ ] GET <URI>/fasta

• [ ] GET <URI>/gff

• [ ] GET <URI>/download

  Successful download Not found due to wrong URI, both with and without accept header text/html Not found due to URI not allowed to access, both with and without accept header text/html For gff, gb, fasta there should be a test to download an object that cannot to convert to these formats both with and without accept header text/html

[jvscholz]

updates issue #1093

[cjmyers]

Also include /summary and add to api docs too (returns JSON)

[cjmyers]

/metadata and /summary return JSON, must compare with diff

/download returns an attachment, so if you attach a text, can compare with diff

All other use SBOL Validator