examples/dataflow/dma: fix simulation, run it for 100 cycles
flow/network: replace NetworkX MultiDiGraph with simple implementation
examples/dataflow: adapt to new simple MultiDiGraph implementation
doc: update for NetowrkX refactoring
test_cordic: stop spewing out numbers
cordic: round() constants if not power of two bitwidth, cleanup, simplify some logic
add ./vpi directory to search path
add travis-ci description