Install BLAST+ in dedicated ~/.sequenceserver dir.

Signed-off-by: Vivek Rai <vivekraiiitkgp@gmail.com>
Find BLAST+ binaries path correctly

Signed-off-by: Vivek Rai <vivekraiiitkgp@gmail.com>
Parameterise BLAST+ download to MINIMUM_BLAST_VERSION constant.

Signed-off-by: Anurag Priyam <anurag08priyam@gmail.com>
Minimum BLAST+ version requirement is now 2.2.30+.

Needed for robust sequence retrieval.

Signed-off-by: Anurag Priyam <anurag08priyam@gmail.com>