Unittest locale_identifiers() and exists() bijection.

[kdeldycke]

I just had a little doubt about the relationship between locale_identifiers() and exists(), so I made a tiny test to make sure the two refers to the same locale IDs taxonomy.

[codecov-io]

Current coverage is 89.66%

Merging #351 into master will increase coverage by +0.02% as of f8e0f06

@@            master    #351   diff @@
======================================
  Files           23      23       
  Stmts         3794    3794       
  Branches         0       0       
  Methods          0       0       
======================================
+ Hit           3401    3402     +1
  Partial          0       0       
+ Missed         393     392     -1

Review entire Coverage Diff as of f8e0f06

Powered by Codecov. Updated on successful CI builds.

[akx]

👍

[kdeldycke]

Thanks @akx ! That was fast ! 😺