Add check for tuning parameters that are not supported by the method

[jmuhlenkamp]

No description provided.

[codecov-io]

Codecov Report

Merging #956 into master will increase coverage by <.01%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master     #956      +/-   ##
==========================================
+ Coverage   19.54%   19.54%   +<.01%     
==========================================
  Files          90       90              
  Lines       12077    12079       +2     
==========================================
+ Hits         2360     2361       +1     
- Misses       9717     9718       +1

Impacted Files	Coverage Δ
R/train.default.R	51.31% <0%> (-0.14%)	⬇️
R/print.train.R	0% <0%> (ø)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 464500b...b55b9a5. Read the comment docs.