Measurement unit abbreviation enhances

Include `national_measurement_units` as part of `formatted_base`
Include `national_measurement_units` as part of `base`

`national_measurement_units` won't be serialised anymore to frontend
sync: log conformance errors if they happen

also send them via API to see them on admin
Merge pull request #196 from bitzesty/measurement-unit-abbreviation-enhances

Measurement unit abbreviation enhances
show missing abbreviation tags for measurement abbreviations
Merge pull request #198 from bitzesty/measurement-abbreviations-enhances

show missing abbreviation tags for `ps/t` abbreviation
do not fatal with simple PKs

For conformance errors, some models' primary key will be a single value and JSON deserialization will fail. Return serialized primary key if deserialization fails
Enhance `NationalMeasurementUnitView`

- show national measurement unit only if available in map (see `NationalMeasurementUnit`)
- use parenthesis `(` instead of brackets `[`
Merge pull request #197 from bitzesty/sync-conformance-errors

sync: log conformance errors if they happen
Merge pull request #200 from bitzesty/enhance-national-measurement-unit-view

Enhance `NationalMeasurementUnit` view
[Rails] update to version 3.2.19
Merge pull request #201 from bitzesty/rails-update-to-3-2-19

[Rails] update to version 3.2.19
Docker Setup