really just core_arch is needed

Author: Lokathor

.travis.yml

@@ -86,7 +86,6 @@ matrix:
         # Pull the target spec up into the current directory and then build
         - mv ci/gba.json gba.json
         - cargo xbuild -p core_arch --target gba.json
-        - cargo xbuild -p std_detect --target gba.json
     - name: "Documentation"
       install: true
       script: ci/dox.sh