drift-wave test fails with latest xBOUT

[mikekryjak]

Our CI uses xBOUT v.0.3.7 and drift-wave passes fine. Same for v.0.3.8, which is a release from last August.
However, it fails on the latest xBOUT master. It looks like the calculated quantities are many orders of magnitude larger now.
We should probably do xBOUT releases more often.

0: w* = 6283185.307179587 sigma_|| = 829962.8306858601
10: sigma/w* = 0.13209268708619643
10: Simple analytic gamma / w* = 0.1952263229056799, omega / w* = 0.25278703831059357
10: Analytic gamma / w* = 0.12307605137334655, omega / w* = 0.08470731415035498
10: gamma = 69404414089976.51, gamma / w* = 11046055.57481655
10: omega = 50045034275552.9, w / w* = 7964914.582157573
10: Running B = 0.3
10: getmpirun: using the default mpirun -np
10: w* = 2094395.1023931957 sigma_|| = 7469665.476172741
10: sigma/w* = 3.566502551327303
10: Simple analytic gamma / w* = 0.21152879235666955, omega / w* = 0.8939588400005435
10: Analytic gamma / w* = 0.43468755296008443, omega / w* = 0.4233873159578562
10: gamma = 82384832911591.31, gamma / w* = 39335860.18103886
10: omega = 85085437799006.56, w / w* = 40625304.032549664