Use relative URLs.

Turns out I didn't make all the relevant changes in
e924f47d1879f7a3e9086d32a5f1d36ca014266d.

Signed-off-by: Anurag Priyam <anurag08priyam@gmail.com>
Rubocop: lib/blast.rb, refactor

Signed-off-by: Vivek Rai <vivekraiiitkgp@gmail.com>