Correctly handle nested types

[rmichela]

Fixes #84

[codecov]

Codecov Report

Merging #85 into master will decrease coverage by 1.1%.
The diff coverage is 0%.

@@             Coverage Diff              @@
##             master      #85      +/-   ##
============================================
- Coverage     71.95%   70.84%   -1.11%     
  Complexity      240      240              
============================================
  Files            38       38              
  Lines           895      909      +14     
  Branches         91       91              
============================================
  Hits            644      644              
- Misses          227      241      +14     
  Partials         24       24

Impacted Files	Coverage Δ	Complexity Δ
...main/java/com/salesforce/jprotoc/ProtoTypeMap.java	5.45% <0%> (-1.22%)	1 <0> (ø)
...main/java/com/salesforce/jprotoc/ProtocPlugin.java	0% <0%> (ø)	0 <0> (ø)	⬇️
...rc/main/java/com/salesforce/jprotoc/Generator.java	0% <0%> (ø)	0 <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 394cfdd...a70de97. Read the comment docs.