Python 3 compatible

There are also some slight changes to the JSON schemas and the use of
JSON-LD.

tests/test_plugins.py

@@ -0,0 +1,71 @@
+#!/bin/env python
+
+import os
+import logging
+import shelve
+import shutil
+import tempfile
+
+import json
+import os
+from unittest import TestCase
+from senpy.models import Results, Entry
+from senpy.plugins import SenpyPlugin, ShelfMixin
+
+
+class ShelfTest(ShelfMixin, SenpyPlugin):
+
+    def test(self, key=None, value=None):
+        assert isinstance(self.sh, shelve.Shelf)
+        assert key in self.sh
+        print('Checking: sh[{}] == {}'.format(key, value))
+        print('SH[{}]: {}'.format(key, self.sh[key]))
+        assert self.sh[key] == value
+        
+
+
+class ModelsTest(TestCase):
+
+
+    def tearDown(self):
+        if os.path.exists(self.shelf_dir):
+            shutil.rmtree(self.shelf_dir)
+
+        if os.path.isfile(self.shelf_file):
+            os.remove(self.shelf_file)
+
+    def setUp(self):
+        self.shelf_dir = tempfile.mkdtemp()
+        self.shelf_file = os.path.join(self.shelf_dir, "shelf")
+        
+    def test_shelf(self):
+        ''' A shelf is created and the value is stored '''
+        a = ShelfTest(info={'name': 'shelve',
+                            'version': 'test',
+                            'shelf_file': self.shelf_file})
+        assert a.sh == {}
+        assert a.shelf_file == self.shelf_file
+
+        a.sh['a'] = 'fromA'
+        a.test(key='a', value='fromA')
+
+        sh = shelve.open(self.shelf_file)
+
+        assert sh['a'] == 'fromA'
+
+
+    def test_two(self):
+        ''' Reusing the values of a previous shelf '''
+        a = ShelfTest(info={'name': 'shelve',
+                            'version': 'test',
+                            'shelf_file': self.shelf_file})
+        print('Shelf file: %s' % a.shelf_file)
+        a.sh['a'] = 'fromA'
+        a.close()
+
+        b = ShelfTest(info={'name': 'shelve',
+                            'version': 'test',
+                            'shelf_file': self.shelf_file})
+        b.test(key='a', value='fromA')
+        b.sh['a'] = 'fromB'
+        assert b.sh['a'] == 'fromB'