clean up test_react README.md + remove TODO (AMReX-Astro#1722)

the timings in the README.md were very out of date and not
useful anymore

unit_test/test_react/README.md

@@ -3,40 +3,3 @@
 This is a unit test that sets up a cube of data (rho, T, and X varying
 along dimensions) and calls the burner on it.  You can specify the integrator
 via `INTEGRATOR_DIR` and the network via `NETWORK_DIR` in the `GNUmakefile`
-
-## CPU Status
-
-This table summarizes tests run with gfortran.
-
-
-| network                | VODE                    | VODE90                  | BS                      | Rosenbrock    |
-|------------------------|-------------------------|-------------------------|-------------------------|---------------|
-| aprox13                | works<br>(6:1517:2393)  | works<br>(6:1517:23793) | works<br>(126:858:4678) | crashes       |
-| aprox19                | works<br>(27:152:8127)  | works<br>(27:152:8127)  | works<br>(72:297:2869)  | runs too long |
-| triple_alpha_plus_cago | works<br>(6:32:1950)    | works<br>(6:32:1950)    | works<br>(126:148:3044) | crashes       |
-| ignition_chamulak      | works<br>(6:6:28)       | works<br>(6:6:28)       | works<br>(144:144:153)  | works (252:252:252) |
-
-
-## Running on GPUs with VODE
-
-To run a GPU test with the VODE integrator and aprox13, do:
-
-```
-make -j COMP=PGI USE_CUDA=TRUE AMREX_USE_CUDA=TRUE USE_GPU_PRAGMA=TRUE NETWORK_DIR=aprox13 EOS_DIR=helmholtz
-```
-
-Tested with PGI 18.10 and CUDA 9.2.148.
-
-To run in a different directory, the following files are necessary to
-run in addition to the executable:
-
-- `helm_table.dat` (will be symlinked in at compile time)
-- `inputs_aprox13`
-- `probin.aprox13`
-- `xin.aprox13`
-
-Then in an interactive session, (e.g. on Summit), do:
-
-```
-jsrun -n 1 -a 1 -g 1 ./[executable] inputs_aprox13
-```