Resolve "MPI: non-blocking and collective demos"

Closes #6

See merge request training/sohpc-training-2021!6

Change log:
* slurm script for non-blocking demos
* add MPI_Gather demo
* add MPI_Reduce demo
* add MPI_Request_free's to heat equation persistent commlunication
  solution
* use 40 cores for collective demos

Resolve "MPI: non-blocking and collective fortran exercises"

Closes #5

See merge request training/sohpc-training-2021!5

Change log:
* add heat equation Fortran exercise code
* add heat equation Fortran solution code
* add complex reduction Fortran exercise code
* add hello_world Fortran exercise code

Resolve "MPI Advanced Techniues Slides"

Closes #7

See merge request training/sohpc-training-2021!4

Resolve "MPI: non-blocking exercises"

Closes #2

See merge request training/sohpc-training-2021!3

Change log:
* add heat_equation exercise code
* add heat_equation solutions code
* add multi_ring solution
* add hello_world exercise code
* add hello_world solution code
* add find_the_deadlock exercises
* add find_the_deadlock solutions
* add complex_reduction exercise code
* add complex_reduction solution code
* add slurm batch scripts

Resolve "MPI: non-blocking slides"

Closes #1

See merge request training/sohpc-training-2021!1

Change log:
* add collective communication slides
* add non-blocking exercises
* add collective exercises
* add non-blocking ping-pong solution
* standardise slides templating
* add data decomposition slide
* add non-blocking vs persistent demo
* add blocking vs non-blocking demo
* add Non-blocking slides