Fix zope_interface and add python3 compatibility

The `zope.interface` module lacks of the __init__.py file in one of his folders, that leads into an ImportError: No module named zope.interface

Author: opacam

pythonforandroid/recipes/zope_interface/__init__.py

@@ -1,5 +1,7 @@
 from pythonforandroid.recipe import PythonRecipe
 from pythonforandroid.toolchain import current_directory
+from pythonforandroid.toolchain import shprint
+from os.path import join, exists
 import sh
 
 
@@ -10,9 +12,19 @@ class ZopeInterfaceRecipe(PythonRecipe):
     url = 'https://pypi.python.org/packages/source/z/zope.interface/zope.interface-{version}.tar.gz'
     site_packages_name = 'zope.interface'
 
-    depends = [('python2', 'python3crystax')]
     patches = ['no_tests.patch']
 
+    def build_arch(self, arch):
+        super(ZopeInterfaceRecipe, self).build_arch(arch)
+        # The zope.interface module lacks of the __init__.py file in one of his
+        # folders, that leads into: ImportError: No module named zope.interface
+        # Here we create the missing `init` file (this affects to version 4.1.3
+        # (is this also true for latest versions of zope.interface?)
+        zope_init_file = join(self.ctx.get_site_packages_dir(arch.arch),
+                              'zope', '__init__.py')
+        if not exists(zope_init_file):
+            shprint(sh.touch, zope_init_file)
+
     def prebuild_arch(self, arch):
         super(ZopeInterfaceRecipe, self).prebuild_arch(arch)
         with current_directory(self.get_build_dir(arch.arch)):