Enhancement: Write license to file

[localheinz]

This PR

• generates the license using a template and writes it to file

Follows #23.

[codecov]

Codecov Report

Merging #28 into master will not change coverage.
The diff coverage is 100%.

@@           Coverage Diff           @@
##             master    #28   +/-   ##
=======================================
  Coverage       100%   100%           
- Complexity       37     44    +7     
=======================================
  Files             8     10    +2     
  Lines           106    130   +24     
=======================================
+ Hits            106    130   +24

Impacted Files	Coverage Δ	Complexity Δ
src/License/Template.php	100% <100%> (ø)	3 <3> (?)
src/License/File.php	100% <100%> (ø)	4 <4> (?)

---

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 6cdb7ec...7c2ac71. Read the comment docs.