remove spec master repo and use Artsy repo for tests as it's more lig…

…htweight

.gitmodules

@@ -1,3 +1,3 @@
-[submodule "spec/fixtures/spec-repos/master"]
-	path = spec/fixtures/spec-repos/master
-	url = https://github.com/CocoaPods/Specs.git
+[submodule "spec/fixtures/spec-repos/artsy"]
+	path = spec/fixtures/spec-repos/artsy
+	url = https://github.com/artsy/Specs.git

.travis.yml

@@ -21,15 +21,6 @@ git:
 before_install:
   - gem install bundler -v "~> 1.17"
   - |
-      master_sha="$(ruby -e "puts '`git submodule status spec/fixtures/spec-repos/master`'.strip.sub(/^-/, '').split(/\s/, 2).first")"
-      curl -ssL "https://github.com/CocoaPods/Specs/archive/$master_sha.tar.gz" | tar xz -C spec/fixtures/spec-repos
-      git rm spec/fixtures/spec-repos/master
-      mv "spec/fixtures/spec-repos/Specs-$master_sha" spec/fixtures/spec-repos/master
-      (
-        cd spec/fixtures/spec-repos/master
-        git init
-        git remote add origin https://github.com/CocoaPods/Specs.git
-      )
       git submodule update --init
       (
         cd spec/fixtures/spec-repos/test_repo