Auto merge of #15078 - servo:jdm-patch-1, r=Ms2ger

Disable test-unit on TravisCI.

Due to #15076, I want to make sure that the TravisCI status is meaningful as much as possible.

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.travis.yml

@@ -13,7 +13,8 @@ matrix:
       script:
          - ./mach build -d --verbose
          - ./mach test-compiletest
-         - ./mach test-unit
+         # disabled due to #15076
+         #- ./mach test-unit
          # disabled due to #14723
          #- ./mach build-geckolib
          #- ./mach test-stylo