changed home-brew installer url

* updated home-brew installer to the correct url. 
When using homebrewalt received this message on install of homebrew
#!/System/Library/Frameworks/Ruby.framework/Versions/Current/usr/bin/ruby

puts <<-EOS
Whoops, the Homebrew installer has moved! Please instead run:

ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

Also, please ask wherever you got this link from to update it to the above.
Thanks!
EOS