tarsnapper: 0.2.1 -> 0.4

- project is not a python library -> move out of pythonPackages.
- also enable tests

pkgs/development/python-modules/tarsnapper-path.patch

@@ -1,20 +0,0 @@
-diff --git a/src/tarsnapper/script.py b/src/tarsnapper/script.py
-index 737ac8d..52cc775 100644
---- a/src/tarsnapper/script.py
-+++ b/src/tarsnapper/script.py
-@@ -48,7 +48,7 @@ class TarsnapBackend(object):
-         """
-         ``arguments`` is a single list of strings.
-         """
--        call_with = ['tarsnap']
-+        call_with = ['@NIXTARSNAPPATH@']
-         for option in self.options:
-             key = option[0]
-             pre = "-" if len(key) == 1 else "--"
-@@ -499,4 +499,4 @@ def run():
- 
- 
- if __name__ == '__main__':
--    run()
-\ No newline at end of file
-+    run()