Update license in Makefile
diff --git a/Makefile b/Makefile
index f88db0a..167cd19 100644
--- a/Makefile
+++ b/Makefile
@@ -1,30 +1,12 @@
-# Copyright (c) 2018, Laurence Lundblade.
-# All rights reserved.
+# Makefile -- UNIX-style make for qcbor as a lib and command line test
#
-# Redistribution and use in source and binary forms, with or without
-# modification, are permitted provided that the following conditions are
-# met:
-# * Redistributions of source code must retain the above copyright
-# notice, this list of conditions and the following disclaimer.
-# * Redistributions in binary form must reproduce the above
-# copyright notice, this list of conditions and the following
-# disclaimer in the documentation and/or other materials provided
-# with the distribution.
-# * The name "Laurence Lundblade" may not be used to
-# endorse or promote products derived from this software without
-# specific prior written permission.
+# Copyright (c) 2018-2019, Laurence Lundblade. All rights reserved.
#
-# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
-# WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
-# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
-# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
-# BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
-# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
-# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
-# BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
-# WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
-# OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
-# IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+# SPDX-License-Identifier: BSD-3-Clause
+#
+# See BSD-3-Clause license in README.md
+#
+
CFLAGS=-I inc -I test -Os -Wall -Werror -pedantic-errors -Wextra -Wshadow -Wparentheses -xc -std=c99