Squashed 'moose-core/' changes from 1b5b9a9..14e2d78

14e2d78 Fixes broken Makefile. Object MMPump.o not found error is resolved by commenting out the object. Either source is missing for it was introduced by recent PR.
aeddce7 Fixes to python3 test command in travis script. Previous fixes passed with python2.
00ad9e2 Fixes to recent Travis build failure.  (#170)
3ebc0a5 Merge commit '5bceacfe'
df5ff48 Merge branch 'difshell' of https://github.com/asiaszmek/moose into asiaszmek-difshell
e4a4bcd Change order of operations to slightly improve accuracy
aacebcc Small changes to make the code more alike genesis and other moose objects
4246932 Difshells and difbuffers initialize close to equilibrium
40a200f Add forgotten setting of helper variables to zero after calculations
dad35e6 Add state in t(i-1)
45c2286 Fix wrong definitions
567444a Fix errors in volume calculation
4e0a857 Indentation
cb40719 Add MMPump to scheduling and makefiles
bfc456c Add MMPump to DifShell
be1ceac Impl...