add IO::Scalar to build_requires

Build.PL

@@ -54,6 +54,7 @@ my $build = Module::Build->new(
     build_requires => {
         'Test::More'   => 0,
         'Test::Output' => 0,
+        'IO::Scalar'   => 0,
     },
 );
 

META.json

@@ -16,6 +16,7 @@
    "prereqs" : {
       "build" : {
          "requires" : {
+            "IO::Scalar" : "0",
             "Test::More" : "0",
             "Test::Output" : "0"
          }

META.yml

@@ -3,6 +3,7 @@ abstract: 'manage the installation of multiple software packages'
 author:
   - unknown
 build_requires:
+  IO::Scalar: '0'
   Test::More: '0'
   Test::Output: '0'
 configure_requires: