build.p6 should probably have a license notice too

Same license as the rest of the project. If you need this code to come under
something less restrictive, contact me and we will figure it out.

build.p6

@@ -1,4 +1,20 @@
 #!/usr/bin/env perl6
+# Copyright © 2016
+#     Aleks-Daniel Jakimenko-Aleksejev <alex.jakimenko@gmail.com>
+#     Daniel Green <ddgreen@gmail.com>
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 # This script will build rakudo for all commits that it can find