Update Polls.csv

Updated with Yougov polls:
http://research.yougov.se/wp-content/uploads/2014/08/YouGovOpinion_Juli2014.pdf
http://research.yougov.se/wp-content/uploads/2014/08/YouGovOpinion_Augusti2014.pdf
Update Polls.csv

Added United minds:
http://www.unitedminds.se/sites/unitedminds.se/files/attachment/UnitedMinds_Aftonbladet%20V%C3%A4ljarbarometer%20rapport%20augv1%202014.pdf
Merge pull request #2 from MansMeg/master

Update