Add first draft of water command

commands/water.py

@@ -0,0 +1,28 @@
+import plugin, os.path, json
+
+def water(user):
+        try:
+                with open(os.path.expanduser("~{}/.botany/visitors.json".format(user))) as f:
+                        visitors = json.load(f)
+                visitors.append(dict(timestamp=int(time.time()),user="cosmicbot"))
+                with open(os.path.expanduser("~{}/.botany/visitors.json".format(user)),"w") as f:
+                        json.dump(visitors,f,indent=2)
+		return True # success
+        except:
+		return False # failed
+
+@plugin.command("water")
+def cmd_water(bot,channel,nick,user=None):
+	if user is not None:
+		if water(user):
+			bot.say(channel,f"Watered {user}'s plant!")
+		else:
+			bot.say(channel,"Unable to water {user}'s plant; are you sure they have one?")
+	else:
+		if water(nick):
+			bot.say(channel,f"Watered {nick}'s plant!")
+			return
+		if water(bot.event.source.user):
+			bot.say(channel,f"Watered {bot.event.source.user}'s plant!")
+			return
+		bot.say(channel,"I couldn't figure out which plant was yours. Give me your username as an argument.")