Anuga py3 (#16)

* Test for pypar_available

* add mpi4py install to travis.ci

* Adding mpi4py

* more tweaking of install scripts

* added a space to if statement

* added metis partition for win32

* setup distribute_mesh for win32

* problem with -m mpi4py on linux

* fix vertices for linux

* print out seq values

* set points for linux

* set vertices to triangles

* set print 0

* set extract submesh

* set rec submesh 1

* set rec submesh 2

* add finalize

* test -m mpi4py

* use -m mpi4py on win32

* use -m mpi4py on win32

* playing with num.long and num.int

* error with blocking

* more play with mpi4py block

* changing mpiexec command

* indent problem

* set dtype for all received arrays

* back to num.int

Co-authored-by: Stephen Roberts <stephen.roberts@anu.edu.au>