[CI] Support doc testing on arbitrary branches

[leezu]

Description

Now that we have a 0.7x release branch, py3-master_gpu_doc must be extended to
support testing documentation on that branch. Previously only master branch and
pull requests were supported.

Checklist

Essentials

• PR's title starts with a category (e.g. [BUGFIX], [MODEL], [TUTORIAL], [FEATURE], [DOC], etc)
• Changes are complete (i.e. I finished coding on this PR)
• All changes have test coverage
• Code is well-documented

[codecov]

Codecov Report

❗ No coverage uploaded for pull request head (supportbranchesforcidocawsbatch@e244ad1). Click here to learn what that means.
The diff coverage is n/a.

[codecov]

Codecov Report

Merging #829 into master will decrease coverage by 0.47%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master     #829      +/-   ##
==========================================
- Coverage   90.48%   90.01%   -0.48%     
==========================================
  Files          66       66              
  Lines        6348     6348              
==========================================
- Hits         5744     5714      -30     
- Misses        604      634      +30

Impacted Files	Coverage Δ
src/gluonnlp/model/parameter.py	92% <0%> (-8%)	⬇️
src/gluonnlp/data/corpora/wikitext.py	94.82% <0%> (-5.18%)	⬇️
src/gluonnlp/data/batchify/batchify.py	92.85% <0%> (-3.58%)	⬇️
src/gluonnlp/data/transforms.py	77.53% <0%> (-2.99%)	⬇️
src/gluonnlp/data/utils.py	74.14% <0%> (-2.05%)	⬇️
src/gluonnlp/data/dataset.py	97.61% <0%> (-1.59%)	⬇️
src/gluonnlp/data/word_embedding_evaluation.py	94.69% <0%> (-0.76%)	⬇️

[mli]

Found link check problems in job PR-829/3:
(line 19) broken https://www.salesforce.com/products/einstein/ai-research/the-wikitext-dependency-language-modeling-dataset/ - 404 Client Error: Not Found for url: https://www.salesforce.com/products/einstein/ai-research/the-wikitext-dependency-language-modeling-dataset/
(line 5) broken https://www.salesforce.com/products/einstein/ai-research/the-wikitext-dependency-language-modeling-dataset/ - 404 Client Error: Not Found for url: https://www.salesforce.com/products/einstein/ai-research/the-wikitext-dependency-language-modeling-dataset/
(line 5) broken https://www.salesforce.com/products/einstein/ai-research/the-wikitext-dependency-language-modeling-dataset/ - 404 Client Error: Not Found for url: https://www.salesforce.com/products/einstein/ai-research/the-wikitext-dependency-language-modeling-dataset/
(line 21) broken https://www.salesforce.com/products/einstein/ai-research/the-wikitext-dependency-language-modeling-dataset/ - 404 Client Error: Not Found for url: https://www.salesforce.com/products/einstein/ai-research/the-wikitext-dependency-language-modeling-dataset/
(line 442) broken https://www.aclweb.org/anthology/P02-1040.pdf)[1 - 404 Client Error: Not Found for url: https://www.aclweb.org/anthology/P02-1040.pdf)%5B1
(line 92) broken https://nlp.stanford.edu/pubs/glove.pdf)[2 - 404 Client Error: NOT FOUND for url: https://nlp.stanford.edu/pubs/glove.pdf)%5B2
(line 208) broken https://www.bioinf.jku.at/publications/older/2604.pdf)[3 - 404 Client Error: Not Found for url: https://www.bioinf.jku.at/publications/older/2604.pdf)%5B3

[mli]

Job PR-829/3 is complete.
Docs are uploaded to http://gluon-nlp-staging.s3-accelerate.dualstack.amazonaws.com/PR-829/3/index.html

[codecov-io]

Codecov Report

Merging #829 into master will decrease coverage by 0.47%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master     #829      +/-   ##
==========================================
- Coverage   90.48%   90.01%   -0.48%     
==========================================
  Files          66       66              
  Lines        6348     6348              
==========================================
- Hits         5744     5714      -30     
- Misses        604      634      +30

Impacted Files	Coverage Δ
src/gluonnlp/model/parameter.py	92% <0%> (-8%)	⬇️
src/gluonnlp/data/corpora/wikitext.py	94.82% <0%> (-5.18%)	⬇️
src/gluonnlp/data/batchify/batchify.py	92.85% <0%> (-3.58%)	⬇️
src/gluonnlp/data/transforms.py	77.53% <0%> (-2.99%)	⬇️
src/gluonnlp/data/utils.py	74.14% <0%> (-2.05%)	⬇️
src/gluonnlp/data/dataset.py	97.61% <0%> (-1.59%)	⬇️
src/gluonnlp/data/word_embedding_evaluation.py	94.69% <0%> (-0.76%)	⬇️