[Spec Fixtures] Add spec with subspecs

spec/fixtures/matryoshka/matryoshka.podspec

+Pod::Spec.new do |s|
+  s.name             = "matryoshka"
+  s.version          = "1.0.0"
+  s.author           = { "Matryona Malyutin" => "matryona@malyutin.local" }
+  s.summary          = "👩‍👩‍👧"
+  s.description      = "Four levels: outmost (root), outer, inner"
+  s.homepage         = "http://httpbin.org/html"
+  s.source           = { :git => "http://malyutin.local/matryoshka.git", :tag => s.version.to_s }
+  s.license          = 'MIT'
+
+  s.source_files = 'Outmost.{h,m}'
+
+  s.default_subspecs = 'Outer'
+
+  s.subspec 'Outer' do |outer_subspec|
+    outer_subspec.source_files = 'Outer/Outer.{h,m}'
+
+    outer_subspec.subspec 'Inner' do |inner_subspec|
+      inner_subspec.source_files = 'Inner/Inner.{h,m}'
+    end
+  end
+
+  s.subspec 'Foo' do |ss|
+    ss.source_files = 'Foo/Foo.{h,m}'
+  end
+
+  s.subspec 'Bar' do |ss|
+    ss.source_files = 'Bar/Bar.{h,m}'
+  end
+end

spec/fixtures/spec-repos/test_repo/matryoshka/1.0.0/matryoshka.podspec.json

+{
+  "name": "matryoshka",
+  "version": "1.0.0",
+  "authors": {
+    "Matryona Malyutin": "matryona@malyutin.local"
+  },
+  "summary": "👩‍👩‍👧",
+  "description": "Four levels: outmost (root), outer, inner",
+  "homepage": "http://httpbin.org/html",
+  "source": {
+    "git": "http://malyutin.local/matroyshka.git",
+    "tag": "1.0.0"
+  },
+  "license": "MIT",
+  "source_files": "Outmost.{h,m}",
+  "default_subspecs": "Outer",
+  "platforms": {
+    "osx": null,
+    "ios": null,
+    "tvos": null,
+    "watchos": null
+  },
+  "subspecs": [
+    {
+      "name": "Outer",
+      "source_files": "Outer/Outer.{h,m}",
+      "subspecs": [
+        {
+          "name": "Inner",
+          "source_files": "Inner/Inner.{h,m}"
+        }
+      ]
+    },
+    {
+      "name": "Foo",
+      "source_files": "Foo/Foo.{h,m}"
+    },
+    {
+      "name": "Bar",
+      "source_files": "Bar/Bar.{h,m}"
+    }
+  ]
+}