Merge pull request #338 from bucaran/fix-run-tests

test runner should search fish_path for specs instead of *

script/run-tests.fish

 #!/usr/bin/env fish
 
 set -l result 0
-for test in (find * -type f -print | grep "spec.fish")
+for test in (find $fish_path -type f -print | grep "spec.fish")
   fish $test $argv
     or set result 1
 end