Invalidate cache on change of apikey / enterprise trail

[patrickjahns]

Fixes #260

When caching is active, the first request would be cached and if the apikey / enterprise trail is started afterward, it would lead to not being able to install enterprise trail apps

Note:
There is still an open scenario, that when the user changes config.php manually to update licensekey and apikey that the cache would persist.

We should document that changing/adding theses values requires a cache invalidation

[codecov-io]

Codecov Report

Merging #282 into master will decrease coverage by 0.09%.
The diff coverage is 0%.

@@             Coverage Diff             @@
##             master     #282     +/-   ##
===========================================
- Coverage      36.1%   36.01%   -0.1%     
  Complexity      228      228             
===========================================
  Files            15       15             
  Lines           770      772      +2     
===========================================
  Hits            278      278             
- Misses          492      494      +2

Impacted Files	Coverage Δ	Complexity Δ
lib/MarketService.php	18.86% <0%> (-0.15%)	100 <0> (ø)

---

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 29b12f2...844cb90. Read the comment docs.

[PVince81]

@patrickjahns codecov fails, any chance to cover the new lines somehow ?

[patrickjahns]

This does not solve the issue 100% -> there seems to be something going on on the marketplace side that causes a delay of propagation when a enterprise trail is started from the market app