only use build_tests/typical/install.rb for Install builder specs

build_tests/typical/echo_command_ruby_builder.rb

@@ -1,7 +1,7 @@
 build do
   Environment.new do |env|
     env.echo = :command
-    env.Install("inst.exe", "install.rb")
+    env.Copy("copy.rb", "echo_command_ruby_builder.rb")
   end
 
 end

spec/build_tests_spec.rb

@@ -896,7 +896,7 @@ EOF
 
     result = run_rscons(rsconscript: "echo_command_ruby_builder.rb")
     expect(result.stderr).to eq ""
-    expect(lines(result.stdout)).to include *["Install install.rb => inst.exe"]
+    expect(lines(result.stdout)).to include *["Copy echo_command_ruby_builder.rb => copy.rb"]
   end
 
   it "supports a string for a builder's echoed 'command' with Environment#print_builder_run_message" do