Added HubAdapter to call Sentry static methods from Integrations

[marandaneto]

#245 was deferred, but we need this change.

[codecov-io]

Codecov Report

Merging #250 into master will increase coverage by 0.07%.
The diff coverage is 6.97%.

@@             Coverage Diff              @@
##             master     #250      +/-   ##
============================================
+ Coverage     57.27%   57.34%   +0.07%     
- Complexity      567      576       +9     
============================================
  Files            72       73       +1     
  Lines          2708     2750      +42     
  Branches        234      234              
============================================
+ Hits           1551     1577      +26     
- Misses         1042     1057      +15     
- Partials        115      116       +1

Impacted Files	Coverage Δ	Complexity Δ
...ntry-core/src/main/java/io/sentry/core/Sentry.java	28.75% <ø> (+28.75%)	6 <0> (+6)	⬆️
sentry-core/src/main/java/io/sentry/core/Hub.java	63.48% <100%> (ø)	52 <0> (ø)	⬇️
...-core/src/main/java/io/sentry/core/HubAdapter.java	4.76% <4.76%> (ø)	2 <2> (?)
...try/core/transport/RetryingThreadPoolExecutor.java	54.83% <0%> (+1.07%)	14% <0%> (+1%)	⬆️

---

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 f01ab69...520ea77. Read the comment docs.