chore(CMakeLists.txt): bump to version 2.15.11

fix(bin/dReach): -k <N> sets the upperbound of unrolling. -u has the …

…same effect

fix(opensmt/egraph/Enode.C): use 16-digit precision when printing Enode

reverted rp_interval_pow to realpaver implementation because of bug i…

…n filib

fix(cmake): add patch version when cpack

[skip ci]

fix(.travis.osx.yml): typo