Fix bug in reconstruction of 'bins' network-attribute from given ranges

Occasionally, the 'bins' attribute did not include the end-date
of the second-last range, as described in Issue #256.

In addition, fix one faulty test.

Signed-off-by: Maximilian Löffler <s8maloef@stud.uni-saarland.de>

tests/test-split-network-time-based.R

@@ -206,7 +206,8 @@ patrick::with_parameters_test_that("Split a network time-based (time.period = ..
     expected.bins = get.date.from.string(c("2016-07-12 15:58:59", "2016-07-12 15:59:59",
                                            "2016-07-12 16:00:59", "2016-07-12 16:01:59",
                                            "2016-07-12 16:02:59", "2016-07-12 16:03:59",
-                                           "2016-07-12 16:04:59", "2016-07-12 16:06:33"))
+                                           "2016-07-12 16:04:59", "2016-07-12 16:05:59",
+                                           "2016-07-12 16:06:33"))
     expect_equal(expected.bins, attr(results, "bins"))
 
     ## check networks

util-split.R

@@ -815,11 +815,9 @@ split.network.time.based.by.ranges = function(network, ranges, remove.isolates =
     )
 
     ## convert ranges to bins
-    bins.starts = sapply(ranges.bounds, function(range) range[1])
-    bins.end = ranges.bounds[[length(ranges.bounds)]][2]
-    bins.date = get.date.from.unix.timestamp(c(bins.starts, bins.end))
+    bins = get.bin.dates.from.ranges(ranges.bounds)
+    attr(nets.split, "bins") = bins
 
-    attr(nets.split, "bins") = bins.date
     return(nets.split)
 }