Fix: Move classes into a different namespace

[localheinz]

This PR

• moves classes into a different namespace

Follows #6.

[codecov]

Codecov Report

Merging #166 into master will not change coverage by %.
The diff coverage is n/a.

@@            Coverage Diff            @@
##             master     #166   +/-   ##
=========================================
  Coverage     98.33%   98.33%           
  Complexity       87       87           
=========================================
  Files            19       19           
  Lines           240      240           
=========================================
  Hits            236      236           
  Misses            4        4           

Impacted Files	Coverage Δ	Complexity Δ
src/Definitions.php	91.30% <ø> (ø)	10.00 <0.00> (?)

---

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 063b45e...4f36835. Read the comment docs.