Create list of challenging WDM test files

[aufdenkampe]

Create a list of WDM test files that have given us challenges, either by fully failing, exploding into overly large files, or other issues. Include some information about what failed previously. Also include a few WDM that have always worked well.

Give this list to @ptomasula & @htaolimno for testing for #21.

Connected to respec#40, and specifically files & comment by @bcous shared in respec#40 (comment)
Nick Grewe (@McGrupp10) has additional information on specific time series that failed.

[aufdenkampe]

These were the most challenging with the original readWDM:

• rpo772.wdm, extracted by @jlkittle from files shared by @bcous via Improve readUCI & readWDM for a broader range of valid files respec/HSPsquared#40 (comment)
• RPO_SWMM48LINKS2017_wCBOD_June2019.wdm, according to @McGrupp10 (Nick)
  • with the following 4 problem DSNs: 130, 160, 862, and 953

[aufdenkampe]

@htaolimno and @ptomasula, we should also make sure for #21 that we can read every WDM file in our test folder and also in the HSPF standard tests folder at https://github.com/respec/FORTRAN/tree/master/test/hspf/standard/Current, as suggested by @ @PaulDudaRESPEC in respec#31 (comment).

[aufdenkampe]

Closing, now that we've completed #21 and soon to merge PR #35.