centrality: no saving functional time-series, begin tests

The functional time-series is no longer saved as an intermediate step and instead the reading of the time-series is in the same node as computing centrality.

Signed-off-by: Zarrar Shehzad <czarrar@gmail.com>
some fixes and beginnings of new normed base correlation
load load
fix to nipype centrality inputs
fix to centrality; add timing to centrality