[Change] Analyze: adapted betas sampling; Tests: adapted beta comparison

Signed-off-by: Oleg Komarov <o.komarov11@imperial.ac.uk>
[Minor] getData: fix (iout,:) instead of (iout)

Signed-off-by: Oleg Komarov <o.komarov11@imperial.ac.uk>
[Add] Tests: detailed Beta check on specific date

Signed-off-by: Oleg Komarov <o.komarov11@imperial.ac.uk>
[Change] fixedsampling: change arguments, simplified, cleaned up, warnings

Signed-off-by: Oleg Komarov <o.komarov11@imperial.ac.uk>
[Minor] Analyze: fixedsampling prices and dates in separate vars

Signed-off-by: Oleg Komarov <o.komarov11@imperial.ac.uk>