Drop the dependency on dukpy

The dukpy tests are failing on windows with VS 2017. Instead use Web
Engine to compile rapydscript code, when the rapydscript binary is not
present.

COPYRIGHT

@@ -4,10 +4,6 @@ License: GPL-3
  The full text of the GPL is distributed as in
  /usr/share/common-licenses/GPL-3 on Debian systems.
 
-Files: src/duktape/*
-Copyright: Various
-License: MIT
-
 Files: resources/content-server/font-awesome/*
 Copyright: Various
 License: MIT and SIL OFL

bypy/sources.json

@@ -639,17 +639,6 @@
         }
     },
 
-    {
-        "name": "dukpy",
-        "python": 2,
-        "unix": {
-            "filename": "dukpy-0.3.tar.gz",
-            "hash": "sha1:31c67f087f9d55798f2c00aba46fa18c3d8fb8aa",
-            "urls": ["https://github.com/kovidgoyal/dukpy/archive/v0.3.tar.gz"]
-        }
-    },
-
-
     {
         "name": "chardet",
         "unix": {

src/calibre/test_build.py

@@ -316,8 +316,6 @@ def find_tests():
     ans = unittest.defaultTestLoader.loadTestsFromTestCase(BuildTest)
     from calibre.utils.icu_test import find_tests
     ans.addTests(find_tests())
-    import duktape.tests as dtests
-    ans.addTests(unittest.defaultTestLoader.loadTestsFromModule(dtests))
     from tinycss.tests.main import find_tests
     ans.addTests(find_tests())
     from calibre.spell.dictionary import find_tests