Use the gwdetchar.io.html.alert utility to render bootstrap alert boxes

[alurban]

This PR refactors and simplifies construction of bootstrap alert boxes by taking advantage of the brand-new gwdetchar.io.html.alert utility available in gwdetchar-1.0.0 (pre-release). Various PEP-8 compliance fixes are also included.

cc @duncanmmacleod

[codecov]

Codecov Report

Merging #283 into master will increase coverage by 0.13%.
The diff coverage is 43.75%.

@@            Coverage Diff             @@
##           master     #283      +/-   ##
==========================================
+ Coverage   38.75%   38.88%   +0.13%     
==========================================
  Files          47       47              
  Lines        7415     7387      -28     
==========================================
- Hits         2873     2872       -1     
+ Misses       4542     4515      -27

Flag	Coverage Δ
#Linux	38.88% <43.75%> (+0.13%)	⬆️
#python35	38.88% <43.75%> (+0.13%)	⬆️
#python36	38.88% <43.75%> (+0.13%)	⬆️
#python37	38.88% <43.75%> (+0.13%)	⬆️

Impacted Files	Coverage Δ
gwsumm/tabs/core.py	31.16% <ø> (-0.32%)	⬇️
gwsumm/tabs/misc.py	44.74% <ø> (ø)	⬆️
gwsumm/tabs/data.py	10.82% <0%> (+0.06%)	⬆️
gwsumm/tabs/etg.py	15.12% <0%> (+0.26%)	⬆️
gwsumm/tabs/guardian.py	19.25% <0%> (+0.6%)	⬆️
gwsumm/html/bootstrap.py	100% <100%> (ø)	⬆️
gwsumm/tabs/fscan.py	16.41% <25%> (+1.08%)	⬆️
gwsumm/tabs/stamp.py	36.84% <50%> (+4.58%)	⬆️
gwsumm/tabs/sei.py	14.84% <66.67%> (ø)	⬆️

---

Continue to review full report at Codecov.

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Δ = absolute <relative> (impact), ø = not affected, ? = missing data
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[codecov]

Codecov Report

Merging #283 into master will increase coverage by 0.13%.
The diff coverage is 43.75%.

@@            Coverage Diff             @@
##           master     #283      +/-   ##
==========================================
+ Coverage   38.75%   38.88%   +0.13%     
==========================================
  Files          47       47              
  Lines        7415     7387      -28     
==========================================
- Hits         2873     2872       -1     
+ Misses       4542     4515      -27

Flag	Coverage Δ
#Linux	38.88% <43.75%> (+0.13%)	⬆️
#python35	38.88% <43.75%> (+0.13%)	⬆️
#python36	38.88% <43.75%> (+0.13%)	⬆️
#python37	38.88% <43.75%> (+0.13%)	⬆️

Impacted Files	Coverage Δ
gwsumm/tabs/core.py	31.16% <ø> (-0.32%)	⬇️
gwsumm/tabs/misc.py	44.74% <ø> (ø)	⬆️
gwsumm/tabs/data.py	10.82% <0%> (+0.06%)	⬆️
gwsumm/tabs/etg.py	15.12% <0%> (+0.26%)	⬆️
gwsumm/tabs/guardian.py	19.25% <0%> (+0.6%)	⬆️
gwsumm/html/bootstrap.py	100% <100%> (ø)	⬆️
gwsumm/tabs/fscan.py	16.41% <25%> (+1.08%)	⬆️
gwsumm/tabs/stamp.py	36.84% <50%> (+4.58%)	⬆️
gwsumm/tabs/sei.py	14.84% <66.67%> (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 a38de90...25e7d13. Read the comment docs.