GIT-2045: enable versioning and strict slash on BlueprintGroup

[harshanarayana]

closes #2045

• Unit Tests
• Update Documentation

[codecov]

Codecov Report

Merging #2047 (2c4cb55) into master (be905e0) will increase coverage by 0.124%.
The diff coverage is 100.000%.

@@              Coverage Diff              @@
##            master     #2047       +/-   ##
=============================================
+ Coverage   91.857%   91.981%   +0.124%     
=============================================
  Files           35        36        +1     
  Lines         3242      3292       +50     
  Branches       556       559        +3     
=============================================
+ Hits          2978      3028       +50     
  Misses         179       179               
  Partials        85        85               

Impacted Files	Coverage Δ
sanic/websocket.py	82.418% <ø> (ø)
sanic/app.py	91.379% <100.000%> (+0.019%)	⬆️
sanic/blueprint_group.py	100.000% <100.000%> (ø)
sanic/blueprints.py	100.000% <100.000%> (ø)
sanic/handlers.py	95.455% <100.000%> (-0.464%)	⬇️
sanic/models/futures.py	100.000% <100.000%> (ø)
sanic/models/handler_types.py	100.000% <100.000%> (ø)
sanic/router.py	94.667% <100.000%> (ø)
sanic/server.py	87.958% <100.000%> (ø)

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[ahopkins]

Don't forget to add test coverage 😎 

[ahopkins]

Thanks for your work on this.

[ahopkins]

Looks good. A couple more minor changes.