libimagequant: remove custom phases, make it a Makefile package

var/spack/repos/builtin/packages/libimagequant/package.py

@@ -4,22 +4,15 @@
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
 
 
-class Libimagequant(Package):
+class Libimagequant(MakefilePackage):
     """Small, portable C library for high-quality conversion of RGBA images to
-    8-bit indexed-color (palette) images."""
+    8-bit indexed-color (palette) images.
+    """
 
     homepage = "https://pngquant.org/lib/"
     url      = "https://github.com/ImageOptim/libimagequant/archive/2.12.6.tar.gz"
 
     version('2.12.6', sha256='b34964512c0dbe550c5f1b394c246c42a988cd73b71a76c5838aa2b4a96e43a0')
 
-    phases = ['configure', 'build', 'install']
-
-    def configure(self, spec, prefix):
+    def edit(self, spec, prefix):
         configure('--prefix=' + prefix)
-
-    def build(self, spec, prefix):
-        make()
-
-    def install(self, spec, prefix):
-        make('install')