+/- block tests failing with v11 beta

[BeksOmega]

The +/- blocks build, but their tests fail.

1) List create block
       Xml
         Serialization
           append block
             0 items:
     AssertionError: expected 5 to equal undefined
      at assertListBlockStructure (webpack-internal:///./test/list_create.mocha.js:38:14)
      at Object.assertBlockStructure (webpack-internal:///./test/list_create.mocha.js:185:11)
      at Context.eval (webpack-internal:///../dev-tools/src/block_test_helpers.mocha.js:197:16)

  2) List create block
       Json
         Serialization
           append block
             0 items:
     AssertionError: expected 5 to equal undefined
      at assertListBlockStructure (webpack-internal:///./test/list_create.mocha.js:38:14)
      at Object.assertBlockStructure (webpack-internal:///./test/list_create.mocha.js:270:11)
      at Context.eval (webpack-internal:///../dev-tools/src/block_test_helpers.mocha.js:197:16)

...This continues with the same error...