Extra trailing tab in "strains.out" files

[aysunrhn]

Both when a canonical quiver is created and when reads are aligned to an existing graph, the output file with the extension strains.out has an extra trailing tab character.

It doesn't affect the internal steps, but it is better to fix it so the output files are easier to use in external tools.

ptolemy/src/main/scala/canonical_quiver/ConstuctCanonicalQuiver.scala

Lines 229 to 231 in f698a0b

	for ((nodeID, i) <- sortedNodeID.zipWithIndex) {
	pws.print(nodeID + "\t")
	strain2Nodes.foreach{p => if (p._2(i)) pws.print("1\t") else pws.print("0\t") }