DockerCertificates from String and InputStream

[tiagoalves83]

Sometimes the docker certificates are storage in other places than files. Maybe DockerCertificates could load from InputStream or String instead of Path / File. This is a suggestion. private methods of DockerCertificates could be protected, and Builder could have InputStreams for cert properties instead of Paths ...

[codecov-io]

Codecov Report

Merging #755 into master will decrease coverage by 2.16%. The diff coverage is 0%.

@@             Coverage Diff              @@
##             master     #755      +/-   ##
============================================
- Coverage     66.38%   64.22%   -2.17%     
- Complexity      738      782      +44     
============================================
  Files           165      158       -7     
  Lines          3130     3712     +582     
  Branches        357      491     +134     
============================================
+ Hits           2078     2384     +306     
- Misses          893     1156     +263     
- Partials        159      172      +13