Fix gotosocial crash in search()

Set a default 1.0.0 version if nothing else alters it so that version
checks don't raise an Exception.

Fixes #249.

mastodon/Mastodon.py

@@ -426,6 +426,10 @@ class Mastodon:
             raise MastodonIllegalArgumentError("Invalid version check method.")
         self.version_check_mode = version_check_mode
 
+        self.mastodon_major = 1
+        self.mastodon_minor = 0
+        self.mastodon_patch = 0
+        
         # Versioning
         if mastodon_version == None and self.version_check_mode != 'none':
             self.retrieve_mastodon_version()