Fix dagmc ci
Created by: pshriwise
This is a fix for recent CI failures regarding DAGMC-enabled builds.
DAGMC recently added a check for static and shared MOAB libraries that was not previously present, causing the CI DAGMC install to fail. While static MOAB libraries are not required for OpenMC's purposes, they are required for certain implementations of DAGMC (namely FLUKA-DAGMC). So historically, both versions of these libraries are expected - even if they weren't necessarily used.
There is an issue open about this in DADMC which will resolve this problem soon hopefully.
MOAB's autotools configuration will build both sets of libraries if
--enable-shared is provided, but its CMake configuration doesn't allow both to be built at once (not without considerable changes anyways). Rather than add autotools to the Travis build, MOAB is built once and installed w/ shared libraries. CMake is then reconfigured and MOAB is installed with static libraries. Fortunately, CMake doesn't rebuild all of the object files the second time, so it shouldn't be a big hit to CI times.
Apologies for any delayed work as a result of this issue.