Handle dicts without CFBundleDisplayName in their info.plist

There seem to be dictionaries whose `info.plist` does not
contain the property `CFBundleDisplayName`.

I wasn't able to reproduce the issue locally because all
the dictionaries Apple allows me to enable on my laptop
do contain that property.

Based on #9, it looks like these problematic dictionaries
do have the `CFBundleName` property. To handle such such
dictionaries, in this change, we introduce a fallback order:
 - `CFBundleDisplayName`
 - `CFBundleName`
 - `CFBundleIdentifier`

We also make sure that if a dictionary doesn't have any of
the above attributes, we ignore the dictionary, log the
error, but do not fail `.dict-import`.

Fixes #9

info.plist

@@ -938,7 +938,7 @@ Subsequent searches should be snappy
 	<key>variablesdontexport</key>
 	<array/>
 	<key>version</key>
-	<string>0.2.5</string>
+	<string>0.2.6</string>
 	<key>webaddress</key>
 	<string>https://github.com/mr-pennyworth/alfred-better-dictionaries</string>
 </dict>

pyapp/BetterDict.py

@@ -241,7 +241,13 @@ def get_dict_id(info):
 
 
 def get_dict_name(info):
-  return info['CFBundleDisplayName']
+  return info.get(
+    'CFBundleDisplayName',
+    info.get(
+      'CFBundleName',
+      info['CFBundleIdentifier'],
+    )
+  )
 
 
 def create_workflow_objects(dict_name, dict_id):
@@ -390,14 +396,17 @@ def list_unimported_dicts(import_base_dir):
       imported = [i['title'] for i in json.load(f)['items']]
 
   for dict_path in all_dict_paths():
-    info = dict_info(dict_path)
-    dict_name = get_dict_name(info)
-    if dict_name in imported:
-      continue
-    alfreditems['items'].append({
-      'title': dict_name,
-      'arg': dict_path
-    })
+    try:
+      info = dict_info(dict_path)
+      dict_name = get_dict_name(info)
+      if dict_name in imported:
+        continue
+      alfreditems['items'].append({
+        'title': dict_name,
+        'arg': dict_path
+      })
+    except Exception as e:
+      print(f'Unable to process "{dict_path}": {e}', file=sys.stderr)
   print(json.dumps(alfreditems, indent=2))