Add locking around skill settings changes

[NeonDaniel]

Add test case to reproduce/resolve #93
Possibly related to #91

[codecov]

Codecov Report

Merging #114 (759ec42) into dev (0cdf027) will increase coverage by 58.34%.
The diff coverage is 76.25%.

@@            Coverage Diff             @@
##             dev     #114       +/-   ##
==========================================
+ Coverage   0.00%   58.34%   +58.34%     
==========================================
  Files         33       33               
  Lines       3173     3222       +49     
==========================================
+ Hits           0     1880     +1880     
+ Misses      3173     1342     -1831     

Impacted Files	Coverage Δ
ovos_workshop/decorators/converse.py	0.00% <0.00%> (ø)
ovos_workshop/decorators/fallback_handler.py	0.00% <0.00%> (ø)
ovos_workshop/skills/active.py	100.00% <ø> (+100.00%)	⬆️
ovos_workshop/skills/decorators/__init__.py	0.00% <0.00%> (ø)
ovos_workshop/skills/decorators/converse.py	0.00% <0.00%> (ø)
...vos_workshop/skills/decorators/fallback_handler.py	0.00% <0.00%> (ø)
ovos_workshop/skills/decorators/killable.py	0.00% <0.00%> (ø)
ovos_workshop/skills/decorators/layers.py	0.00% <0.00%> (ø)
ovos_workshop/skills/decorators/ocp.py	0.00% <0.00%> (ø)
ovos_workshop/skills/intent_provider.py	0.00% <0.00%> (ø)
... and 13 more

... and 9 files with indirect coverage changes