Revert exception raising until more confidence in registration system exists.

Having spoken to @mihostet late last year about it, I have reverted the automatic raising of exceptions when registering a new package with cmmnbuild-dep-manager.

This will ease the changes in the next release (v2.3.0) which I plan to release over the coming days (in order to fix the issue with incorrectly determining whether cbng-web is available.

cmmnbuild_dep_manager/tests/test_cmmnbuild_dep_manager.py

@@ -69,22 +69,25 @@ def test_no_such_module(caplog, simple_resolver):
     ]
 
 
-def test_module_missing_special_resolver_attr(simple_resolver):
+def test_module_missing_special_resolver_attr(caplog, simple_resolver):
     with tmp_mod('a_cmmnbuild_test_module'):
-        with pytest.raises(AttributeError) as err:
-            cbdm.Manager('a_cmmnbuild_test_module')
-    assert str(err.value) == (
-        "module a_cmmnbuild_test_module does not declare "
-        "__test_resolver_deps__, which is needed for SimpleResolver "
-        "(The test resolver which does nothing) ")
+        cbdm.Manager('a_cmmnbuild_test_module')
 
+    warning = (
+        "cmmnbuild_dep_manager", logging.ERROR,
+        'module a_cmmnbuild_test_module does not declare '
+        '__test_resolver_deps__, which is needed for SimpleResolver '
+        '(The test resolver which does nothing) ')
+    assert warning in caplog.record_tuples
 
-def test_module_dependencies_no_version(simple_resolver):
+
+def test_module_dependencies_no_version(caplog, simple_resolver):
     with tmp_mod('a_cmmnbuild_test_module', dependencies=['j1', 'j2']):
-        with pytest.raises(AttributeError) as err:
-            cbdm.Manager('a_cmmnbuild_test_module')
-    assert str(err.value) == (
+        cbdm.Manager('a_cmmnbuild_test_module')
+    warning = (
+        "cmmnbuild_dep_manager", logging.ERROR,
         "module 'a_cmmnbuild_test_module' has no attribute '__version__'")
+    assert warning in caplog.record_tuples
 
 
 @contextmanager