Dockerfile updates

[rca]

Hello,

This pull request changes Dockerfile so that the local working copy of localshop is built into a Docker image. This is completely different from the way it currently works; feedback welcome.

Thank you.

[codecov]

Codecov Report

Merging #189 into develop will increase coverage by 3.12%.
The diff coverage is n/a.

@@             Coverage Diff             @@
##           develop     #189      +/-   ##
===========================================
+ Coverage    82.15%   85.28%   +3.12%     
===========================================
  Files           36       33       -3     
  Lines         1390     1155     -235     
===========================================
- Hits          1142      985     -157     
+ Misses         248      170      -78

Impacted Files	Coverage Δ
localshop/apps/dashboard/views.py	57.14% <0%> (-4.1%)	⬇️
localshop/apps/dashboard/urls.py	100% <0%> (ø)	⬆️
localshop/__init__.py
localshop/utils.py
localshop/views.py
localshop/urls.py
localshop/apps/permissions/migrations/__init__.py	100% <0%> (ø)
localshop/apps/permissions/utils.py	92.5% <0%> (+9.16%)	⬆️

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[rca]

Checking in on this, ping @mvantellingen