dev: tests: Unit test for symmetrical=true parse error (bnc#863736)
high: cibconfig: Handle non-string arguments (bnc#863736)
Handle non-string arguments when creating XML nodes.

Convert to "true"/"false" if boolean, else raise error.
test: Unit test for colocation sequential=true
low: cibconfig: do not format xml tags when requested (bnc#863746)
dev: tests: print XML format if failing test