tests-5.3-5

Setting tag tests-5.3-5
dropped the pl sfa rspec_style in default config
dropped slice manager, sfi talks to AM directly
bump ram to 1.5Gb
Substrate probes for total memory
rename sfa-add-* steps into sfa-register-*
new steps sfa-remove-user sfa-insert-user-in-slice sfi-show-slice sfi-show-slice-researchers
sfi-show-site slice-fs-deleted slice-fs-present super-speed-up-slices
new macros sfa-populate sfa-delete sfa-user-slice slice-up slice-down slice-up-down
sfa-get-expires pending