Write tests & run test on BASELINe for single-sequence input

[Julian Zhou]

• make sure that code runs (summarizeBaseline() was recently found broken when baseline@pdf[[1]] is a numeric vector instead of a matrix).

• make sure that result from calcBaseline(db[1, ]) matches the corresponding part of the result from calcBaseline(db[1:3, ]), etc.

[Julian Zhou]

Done. Permanent fix and testing