Reformat and lint Bazel rules, minor CI changes

[jesec]

See commit messages for more info.

---

This change is 

[codecov]

Codecov Report

Merging #199 (1c8c499) into master (397a403) will increase coverage by 2.76%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master     #199      +/-   ##
==========================================
+ Coverage   64.03%   66.80%   +2.76%     
==========================================
  Files          76       76              
  Lines       11053    11053              
==========================================
+ Hits         7078     7384     +306     
+ Misses       3975     3669     -306     

Impacted Files	Coverage Δ
core/node.cpp	54.51% <0.00%> (+0.60%)	⬆️
elab/lnast.cpp	78.50% <0.00%> (+0.62%)	⬆️
task/thread_pool.hpp	70.17% <0.00%> (+1.75%)	⬆️
core/node_pin.cpp	66.37% <0.00%> (+2.04%)	⬆️
core/lgraph.cpp	80.22% <0.00%> (+2.22%)	⬆️
core/graph_library.cpp	61.61% <0.00%> (+2.44%)	⬆️
core/cell.hpp	72.15% <0.00%> (+6.32%)	⬆️
core/lgraph.hpp	83.33% <0.00%> (+9.09%)	⬆️
core/graph_library.hpp	84.61% <0.00%> (+14.28%)	⬆️
core/lgraph_each.cpp	88.57% <0.00%> (+14.28%)	⬆️
... and 2 more

---

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 9d41ad3...1c8c499. Read the comment docs.

[mithro]

BTW See also https://github.com/hdl/bazel_rules_hdl and #186