Implemented basic input function and tested for the three test cases
Added unittests and made style changes
Added DataPacket, AcknowledgementPacket, RoutingUpdatePacket, and FINPacket Classes

Out of the new packet classes, only RoutingUpdatePacket had a new
attribute (table of distance estimates). All other classes instantiated
base Packet class while setting the packet_type field.

Also updated test file to cover initialization of the new packet
classes.
EOF newline
Merge branch 'master' of https://github.com/kexinrong/NetworkSimulator into Input
Changed case_i to CASE_i
Merged classes into single file

Also shortened names of some packet attributes.
More variable name shortening
Merge pull request #6 from kexinrong/Packet

Added DataPacket, AcknowledgementPacket, RoutingUpdatePacket, and FINPacket Classes
Merge branch 'master' of github.com:kexinrong/NetworkSimulator
Adding env.py for the main env
Merge branch 'master' of github.com:kexinrong/NetworkSimulator
Fixed case_i to CASE_i everywhere
(I had missed some last time)
Merge pull request #5 from kexinrong/Input

Implemented basic input function and tested for the three test cases
Merge branch 'master' into Output

Conflicts:
	__pycache__/Packet.cpython-34.pyc