Add 'add tag' method, tags tests

apps/cic-cache/cic_cache/runnable/daemons/filters/base.py

@@ -1,2 +1,15 @@
-class SyncFilter:
-    pass
+class TagSyncFilter:
+
+    def __init__(self, name, domain=None):
+        self.tag_name = name
+        self.tag_domain = domain
+
+
+    def tag(self):
+        return (self.tag_name, self.tag_domain)
+
+
+    def __str__(self):
+        if tag_domain == None:
+            return self.tag_name
+        return '{}.{}'.format(self.tag_domain, self.tag_name)

apps/cic-cache/cic_cache/runnable/daemons/filters/erc20.py

@@ -21,9 +21,10 @@ from cic_cache import db as cic_cache_db
 logg = logging.getLogger().getChild(__name__)
 
 
-class ERC20TransferFilter(SyncFilter):
+class ERC20TransferFilter(TagSyncFilter):
 
     def __init__(self, chain_spec):
+        super(TagSyncFilter, self).__init__('transfer', 'erc20')
         self.chain_spec = chain_spec