Rename add_option to add_group and add_groups

The name of the method in different classes was the same, although each
one did another thing. Renamed some of them to reflect the actual task.

did/cli.py

@@ -68,7 +68,7 @@ def __init__(self, arguments=None):
         # Create sample stats and include all stats objects options
         log.debug("Loading Sample Stats group to build Options")
         self.sample_stats = UserStats()
-        self.sample_stats.add_option(self.parser)
+        self.sample_stats.add_groups(self.parser)
         log.info("Default command line: did {0}".format(" ".join(
             [f'--{stat.option}' for stat in self.sample_stats.stats])))
 

did/stats.py

@@ -140,7 +140,7 @@ class StatsGroup(Stats, metaclass=StatsGroupPlugin):
     # Default order
     order = 500
 
-    def add_option(self, parser):
+    def add_group(self, parser):
         """ Add option group and all children options. """
 
         group = parser.add_argument_group(self.name)
@@ -240,10 +240,10 @@ def configured_plugins(self, config):
             results.append(obj)
         return sorted(results, key=lambda x: x.order)
 
-    def add_option(self, parser):
+    def add_groups(self, parser):
         """ Add options for each stats group. """
         for stat in self.stats:
-            stat.add_option(parser)
+            stat.add_group(parser)
 
 # ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 #  Header & Footer