Add libcerf package

Add pre-built binaries

packages/libcerf.rb

+require 'package'
+
+class Libcerf < Package
+  description 'a self-contained numeric library that provides an efficient and accurate implementation of complex error functions, along with Dawson, Faddeeva, and Voigt functions.'
+  homepage 'http://apps.jcns.fz-juelich.de/doku/sc/libcerf'
+  version '1.5'
+  source_url 'http://apps.jcns.fz-juelich.de/src/libcerf/libcerf-1.5.tgz'
+  source_sha256 'e36dc147e7fff81143074a21550c259b5aac1b99fc314fc0ae33294231ca5c86'
+
+  binary_url ({
+    aarch64: 'https://dl.bintray.com/chromebrew/chromebrew/libcerf-1.5-chromeos-armv7l.tar.xz',
+     armv7l: 'https://dl.bintray.com/chromebrew/chromebrew/libcerf-1.5-chromeos-armv7l.tar.xz',
+       i686: 'https://dl.bintray.com/chromebrew/chromebrew/libcerf-1.5-chromeos-i686.tar.xz',
+     x86_64: 'https://dl.bintray.com/chromebrew/chromebrew/libcerf-1.5-chromeos-x86_64.tar.xz',
+  })
+  binary_sha256 ({
+    aarch64: '94fc2717e970fb97ce0c508a191c5249b99af6b5f29f0855c7494593b827c063',
+     armv7l: '94fc2717e970fb97ce0c508a191c5249b99af6b5f29f0855c7494593b827c063',
+       i686: 'e5e03923be7e965ee27e56b38a1d6dc147dcab47bf01837f8db44fbdde76cc99',
+     x86_64: '0ab2007863a453cd498c9a2be2ffd42ea37e3c469cb1874547916a0375482a0c',
+  })
+
+  def self.build
+    system "./configure --prefix=#{CREW_PREFIX} --libdir=#{CREW_LIB_PREFIX}"
+    system 'make'
+  end
+
+  def self.install
+    system "make", "DESTDIR=#{CREW_DEST_DIR}", "install"
+  end
+end