Raise deprecation warning for httplib2_certs usage

Refs #30.

extra/requirements-net.txt

@@ -1 +1,2 @@
+deprecation>=2.0.6
 httplib2>=0.10,<0.12

jnrbase/httplib2_certs.py

@@ -24,6 +24,7 @@
 from pathlib import Path
 
 import httplib2
+from deprecation import deprecated
 
 #: Allow fallback to bundled httplib2 certs.
 #:
@@ -42,6 +43,8 @@
 }
 
 
+@deprecated(deprecated_in='1.2', removed_in='1.3',
+            details='httplib2 support is being removed')
 def find_certs() -> Path:
     """Find suitable certificates for ``httplib2``.
 

setup.cfg

@@ -86,6 +86,8 @@ filterwarnings =
     error
     # FIXME: This is *only* here until a new jinja release comes
     ignore:Using or importing the ABCs from 'collections'.*:DeprecationWarning
+    ignore:find_certs is deprecated.*:deprecation.DeprecatedWarning
+
 minversion = 4.0
 
 [pycodestyle]

tests/test_httplib2_certs.py

@@ -22,6 +22,7 @@
 
 from pytest import mark, raises, warns
 
+from jnrbase._version import tuple as vtuple
 from jnrbase import httplib2_certs
 
 from .utils import func_attr
@@ -46,7 +47,7 @@ def test_unbundled_package_import(monkeypatch):
 def test_bundled(path_exists_force):
     with warns(RuntimeWarning) as record:
         httplib2_certs.find_certs()
-    assert 'falling back' in record[0].message.args[0]
+    assert 'falling back' in record[1].message.args[0]
 
 
 @exists_result(False)
@@ -86,3 +87,7 @@ def test_curl_bundle(monkeypatch):
     monkeypatch.setattr('jnrbase.httplib2_certs.Path.exists', lambda p: False)
     monkeypatch.setenv('CURL_CA_BUNDLE', 'silly_platform_user')
     assert httplib2_certs.find_certs() == Path('silly_platform_user')
+
+
+def test_removed():
+    assert vtuple < (1, 3), 'httplib2 support should have been removed!'