I have just looked on MacRumours and found out that Apple have stopped support for installing Windows 7 with BootCamp on the 2015 MacBooks (Air and Pro) (link). Since I am going to get the new 12" MacBook I am guessing that too doesn't support Windows 7 using bootcamp.
Since Apple are stopping the drivers for the 2015 models as well, is there still a way to install Windows 7 on the 2015 versions of the MacBook? (I sometimes need Windows 7 on my Mac for college)
Edit
Thank you for the replies.
I ended up getting the MacBook Pro since they didn't have any MacBooks in store. Since I have the MacBook Pro I can now run Windows 7 in a virtual machine (as suggested by you) because I do not have heat and performance issues.