Ensure files opened in from_disk are closed

Fixes [issue 1706](https://github.com/explosion/spaCy/issues/1706).

spacy/language.py

@@ -624,7 +624,7 @@ class Language(object):
         deserializers = OrderedDict((
             ('vocab', lambda p: self.vocab.from_disk(p)),
             ('tokenizer', lambda p: self.tokenizer.from_disk(p, vocab=False)),
-            ('meta.json', lambda p: self.meta.update(ujson.load(p.open('r'))))
+            ('meta.json', lambda p: self.meta.update(util.read_json(p)))
         ))
         for name, proc in self.pipeline:
             if name in disable:

spacy/pipeline.pyx

@@ -214,7 +214,8 @@ class Pipe(object):
 
 def _load_cfg(path):
     if path.exists():
-        return ujson.load(path.open())
+        with path.open() as file_:
+            return ujson.load(file_)
     else:
         return {}
 
@@ -580,7 +581,8 @@ class Tagger(Pipe):
         def load_model(p):
             if self.model is True:
                 self.model = self.Model(self.vocab.morphology.n_tags, **self.cfg)
-            self.model.from_bytes(p.open('rb').read())
+            with p.open('rb') as file_:
+                self.model.from_bytes(file_.read())
 
         def load_tag_map(p):
             with p.open('rb') as file_:

spacy/syntax/nn_parser.pyx

@@ -887,7 +887,7 @@ cdef class Parser:
         deserializers = {
             'vocab': lambda p: self.vocab.from_disk(p),
             'moves': lambda p: self.moves.from_disk(p, strings=False),
-            'cfg': lambda p: self.cfg.update(ujson.load(p.open())),
+            'cfg': lambda p: self.cfg.update(util.read_json(p)),
             'model': lambda p: None
         }
         util.from_disk(path, deserializers, exclude)

spacy/tests/serialize/test_serialize_language.py

@@ -0,0 +1,28 @@
+# coding: utf-8
+from __future__ import unicode_literals
+
+from ..util import make_tempdir
+from ...language import Language
+
+import pytest
+
+
+@pytest.fixture
+def meta_data():
+    return {
+        'name': 'name-in-fixture',
+        'version': 'version-in-fixture',
+        'description': 'description-in-fixture',
+        'author': 'author-in-fixture',
+        'email': 'email-in-fixture',
+        'url': 'url-in-fixture',
+        'license': 'license-in-fixture',
+    }
+
+
+def test_serialize_language_meta_disk(meta_data):
+    language = Language(meta=meta_data)
+    with make_tempdir() as d:
+        language.to_disk(d)
+        new_language = Language().from_disk(d)
+    assert new_language.meta == language.meta

spacy/vectors.pyx

@@ -347,7 +347,8 @@ cdef class Vectors:
         """
         def load_key2row(path):
             if path.exists():
-                self.key2row = msgpack.load(path.open('rb'))
+                with path.open('rb') as file_:
+                    self.key2row = msgpack.load(file_)
             for key, row in self.key2row.items():
                 if row in self._unset:
                     self._unset.remove(row)