Fix UTF-8 encoding issue with weather segment

Closes #172.

powerline/segments/common.py

@@ -135,8 +135,8 @@ def weather(unit='c', location_query=None):
 			return None
 	query_data = {
 		'q':
-			'use "http://github.com/yql/yql-tables/raw/master/weather/weather.bylocation.xml" as we;'
-			'select * from we where location="{0}" and unit="{1}"'.format(location_query, unit),
+			u'use "http://github.com/yql/yql-tables/raw/master/weather/weather.bylocation.xml" as we;'
+			u'select * from we where location="{0}" and unit="{1}"'.format(location_query, unit).encode('utf-8'),
 		'format': 'json'
 	}
 	try: