Allow passing only to suites with skip lists

[travisperson]

If a suite of tests has a skip array, when adding a only: true, the skipped tests start to run again, which makes it hard to isolate a suite. This change allows skipped tests to be skipped and not have the only applied. This results in the tests not showing up in the output.

Example

  tests.key(defaultCommonFactory, {
    only: true,
    skip: [
      // key.export
      {
        name: 'export',
        reason: 'TODO not implemented in go-ipfs yet'
      },
      // key.import
      {
        name: 'import',
        reason: 'TODO not implemented in go-ipfs yet'
      }
    ]
  })

Output

Before

  interface-ipfs-core tests
    .key.gen
      ✓ should generate a new rsa key (106ms)
    .key.list
      ✓ should list all the keys (246ms)
    .key.rename
      ✓ should rename a key (156ms)
    .key.rm
      ✓ should rm a key (178ms)
    .key.export
      1) should export "self" key
    .key.import
      2) should import an exported key


  4 passing (3s)
  2 failing

After

  interface-ipfs-core tests
    .key.gen
      ✓ should generate a new rsa key (175ms)
    .key.list
      ✓ should list all the keys (182ms)
    .key.rename
      ✓ should rename a key (207ms)
    .key.rm
      ✓ should rm a key (97ms)

  4 passing (2s)

[alanshaw]

Good catch!