python-attrs: new package

From the README:

attrs is an MIT-licensed Python package with class decorators that ease
the chores of implementing the most common attribute-related object
protocols.

Signed-off-by: Jeffery To <jeffery.to@gmail.com>

lang/python-attrs/Makefile

@@ -0,0 +1,47 @@
+#
+# Copyright (C) 2016 OpenWrt.org
+#
+# This is free software, licensed under the GNU General Public License v2.
+# See /LICENSE for more information.
+#
+
+include $(TOPDIR)/rules.mk
+
+PKG_NAME:=attrs
+PKG_VERSION:=15.2.0
+PKG_RELEASE:=1
+
+PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.gz
+PKG_SOURCE_URL:=https://pypi.python.org/packages/source/a/attrs
+PKG_MD5SUM:=b3c460eb6482f6e557c0e4025475c007
+
+PKG_BUILD_DEPENDS:=python python-setuptools
+
+PKG_LICENSE:=MIT
+PKG_LICENSE_FILES:=LICENSE
+PKG_MAINTAINER:=Jeffery To <jeffery.to@gmail.com>
+
+include $(INCLUDE_DIR)/package.mk
+$(call include_mk, python-package.mk)
+
+define Package/python-attrs
+	SECTION:=lang
+	CATEGORY:=Languages
+	SUBMENU:=Python
+	TITLE:=python-attrs
+	URL:=https://attrs.readthedocs.org/
+	DEPENDS:=+python-light
+endef
+
+define Package/python-attrs/description
+attrs is an MIT-licensed Python package with class decorators that ease
+the chores of implementing the most common attribute-related object
+protocols.
+endef
+
+define Build/Compile
+	$(call Build/Compile/PyMod,,install --prefix="/usr" --root="$(PKG_INSTALL_DIR)")
+endef
+
+$(eval $(call PyPackage,python-attrs))
+$(eval $(call BuildPackage,python-attrs))