Switched to numo-narray-alt

Author: ankane

Gemfile

@@ -6,12 +6,6 @@ gem "rake"
 gem "minitest"
 gem "csv"
 gem "matrix"
+gem "numo-narray-alt", platform: [:mri, :windows]
 gem "rover-df", platform: [:mri, :windows]
 gem "ruby_memcheck"
-
-# TODO remove when numo-narray > 0.9.2.1 is released
-if Gem.win_platform?
-  gem "numo-narray", github: "ruby-numo/numo-narray", ref: "421feddb46cac5145d69067fc1ac3ba3c434f668"
-else
-  gem "numo-narray", platform: [:mri, :windows]
-end