Build pipelines sometimes fail to pass tests

[merlos]

Whereas in my dev environment unit testing works in build pipelines in github and in travisCI fail most of the time.

Primarily these are the expectations that do not work most of the time

✗ a_DiskCache__can_find_a_file_that_is_in_the_cache, expected to equal <4096>, got <8192>
✗ a_DiskCache__can_remove_the_file_from_the_cache, expected to eventually equal <4096>, got <8192>
✗ a_DiskCache__can_remove_the_file_from_the_cache, expected to eventually equal <0>, got <4096>

MapCache_Tests.DiskCacheSpecs

a_DiskCache__can_find_a_file_that_is_in_the_cache, expected to equal <4096>, got <8192>

/Users/travis/build/merlos/MapCache/Example/Tests/DiskCache/DiskCacheSpecs.swift:111

              diskCache.setDataSync(data1!, forKey: filename1)
              expect(diskCache.diskSize).to(equal(4096))

a_DiskCache__can_remove_the_file_from_the_cache, expected to eventually equal <4096>, got <8192>

/Users/travis/build/merlos/MapCache/Example/Tests/DiskCache/DiskCacheSpecs.swift:151

         diskCache.setDataSync(data1!, forKey: filename1)
         expect(diskCache.diskSize).toEventually(equal(4096))
          // remove the file

a_DiskCache__can_remove_the_file_from_the_cache, expected to eventually equal <0>, got <4096>
/Users/travis/build/merlos/MapCache/Example/Tests/DiskCache/DiskCacheSpecs.swift:155

              expect(diskCache.diskSize).toEventually(equal(0))