Working on TCP Throughput calks

added some more options in main for which file is imported (this way I
can use the csv returned by stdev/median appending)

STDS:
- added function for adding TCP Throughput to csv (function commented
out currently)

SpeedTestFile:
- added function for adding TCP Throughput to csv (function commented
out currently)

utils
- added function for actually calculating the theoretical TCP
Throughput, given RTT, MSS, and Loss.