A fix to conditional causal effects

This version fixes an incorrect graph definition in the IDC algorithm for conditional causal effects.

causaleffect 1.3.12 release

This release eliminates the 'ggm' package dependency. This should make installation easier, due to 'graph' package being removed from CRAN (which ggm depends on). The 'XML' package has also been moved to suggested packages, and is no longer a requirement.

First causaleffect GitHub release

causaleffect package now on GitHub.