add support for setting the exact required memory

[smoors]

this is useful in 2 use cases:

• when testing a PR, to make sure the memory requirements are ok
• when comparing performance between partitions with different amounts of memory available

[casparvl]

Tested, works like a charm.

Again, just want to make sure that your changes to the logging in hooks.py were intentional. If so, this is good to go.

[casparvl]

Oh, fun fact: I tried with the LAMMPS test. That now got killed by the OOM killer xD So I guess your feature is a useful one, and I guess that memory requirement needs to be increased... #217

[smoors]

Again, just want to make sure that your changes to the logging in hooks.py were intentional. If so, this is good to go.

yes, intentional :)
just making sure we're always using reframe warnings + some simplifications

[casparvl]

@smoors if you can resolve the conflict, this is ready to be merged imho