Add __reduce__ to Tokenizer so that English pickles.

- Add tests to test_pickle and test_tokenizer that save to tempfiles.

spacy/tokenizer.pxd

@@ -19,6 +19,7 @@ cdef class Tokenizer:
     cdef object _prefix_re
     cdef object _suffix_re
     cdef object _infix_re
+    cdef object _rules
 
     cpdef Doc tokens_from_list(self, list strings)
 

spacy/tokenizer.pyx

@@ -29,6 +29,16 @@ cdef class Tokenizer:
         self._infix_re = infix_re
         self.vocab = vocab
         self._load_special_tokenization(rules)
+        self._rules = rules
+
+    def __reduce__(self):
+        args = (self.vocab, 
+                self._rules, 
+                self._prefix_re, 
+                self._suffix_re, 
+                self._infix_re)
+
+        return (self.__class__, args, None, None)
 
     @classmethod
     def from_dir(cls, Vocab vocab, data_dir):

tests/test_pickle.py

@@ -1,8 +1,9 @@
-import pytest
-import io
 import cloudpickle
+import io
+import os
 import pickle
-
+import pytest
+import tempfile
 
 @pytest.mark.models
 def test_pickle_english(EN):
@@ -12,4 +13,15 @@ def test_pickle_english(EN):
     file_.seek(0)
 
     loaded = pickle.load(file_)
+    assert loaded is not None
 
+@pytest.mark.models
+def test_cloudpickle_to_file(EN):
+    f = tempfile.NamedTemporaryFile(delete=False)
+    p = cloudpickle.CloudPickler(f)
+    p.dump(EN)
+    f.close()
+    loaded_en = cloudpickle.load(open(f.name))
+    os.unlink(f.name)
+    doc = loaded_en(unicode('test parse'))
+    assert len(doc) == 2

tests/tokenizer/test_tokenizer.py

@@ -2,6 +2,19 @@
 from __future__ import unicode_literals
 
 import pytest
+import io
+import pickle
+import cloudpickle
+import tempfile
+
+
+@pytest.mark.models
+def test_pickle(en_tokenizer):
+    file_ = io.BytesIO()
+    cloudpickle.dump(en_tokenizer, file_)
+    file_.seek(0)
+    loaded = pickle.load(file_)
+    assert loaded is not None
 
 
 def test_no_word(en_tokenizer):