Hardcode shared library extension to .so

Evidently that's what Ruby expects it to be, regardless of target OS.

Author: malept

lib/thermite/config.rb

@@ -112,7 +112,7 @@ def library_name
     #
     def cargo_shared_library
       @cargo_shared_library ||= begin
-        filename = shared_library
+        filename = "#{library_name}.#{shared_ext}"
         filename = "lib#{filename}" unless Gem.win_platform?
         filename
       end
@@ -122,7 +122,7 @@ def cargo_shared_library
     # The basename of the Rust shared library, as installed in the {#ruby_extension_path}.
     #
     def shared_library
-      @shared_library ||= "#{library_name}.#{shared_ext}"
+      @shared_library ||= "#{library_name}.so"
     end
 
     #

test/lib/thermite/config_test.rb

@@ -74,14 +74,14 @@ def test_shared_library
       config.stubs(:library_name).returns('foobar')
       config.stubs(:shared_ext).returns('ext')
       Gem.stubs(:win_platform?).returns(false)
-      assert_equal 'foobar.ext', config.shared_library
+      assert_equal 'foobar.so', config.shared_library
     end
 
     def test_shared_library_windows
       config.stubs(:library_name).returns('foobar')
       config.stubs(:shared_ext).returns('ext')
       Gem.stubs(:win_platform?).returns(true)
-      assert_equal 'foobar.ext', config.shared_library
+      assert_equal 'foobar.so', config.shared_library
     end
 
     def test_cargo_shared_library