added CAS, EC, GSBL, RTECS search options to get_etoxid()

[andschar]

I've added features to query the ETOX data-base by CAS, EC, GSBL, RTECS numbers in addition to the already existing option to search for names (as discussed in #237).

NB: I've added examples and tests for all the new features except for RETCS-numbers, which seems to be a proprietary format, for which I only found rather old publications. I left it there nonetheless.

PR task list:

• Update NEWS
• Add tests (if appropriate)
• Update documentation with devtools::document()
• Check package passed

[codecov-io]

Codecov Report

Merging #241 into master will not change coverage.
The diff coverage is 0.00%.

@@          Coverage Diff           @@
##           master    #241   +/-   ##
======================================
  Coverage    0.00%   0.00%           
======================================
  Files          19      19           
  Lines        1672    1685   +13     
======================================
- Misses       1672    1685   +13     

Impacted Files	Coverage Δ
R/etox.R	0.00% <0.00%> (ø)

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[Aariq]

Haven't tested it out, but looks great in format. I think there needs to be a bit more documentation for the lesser-known options for from=.

[andschar]

Sorry for the mess. Don't know why travis check is failing. Could it be because of man/nist_ri.Rd? It doesn't seem to be built.

[stitam]

According to log it has to do with cts_compinfo(), the server seems to be down. I think @Aariq had the same problem in PR #232. While this is something we have to know about, maybe it shouldn't cause a build to fail. I suggest we ignore if Travis is failing because of cts_compinfo() but open a separate issue for the topic and discuss how to handle these situations.

[Aariq]

According to log it has to do with cts_compinfo(), the server seems to be down. I think @Aariq had the same problem in PR #232. While this is something we have to know about, maybe it shouldn't cause a build to fail. I suggest we ignore if Travis is failing because of cts_compinfo() but open a separate issue for the topic and discuss how to handle these situations.

It only fails on the development build of R. It passes with the release build of R. I can't figure out why either.