Added some tests for IdlGenerator

[codecov[bot]]

Codecov Report

Merging #4 into master will increase coverage by 4.73%. The diff coverage is 98%.

@@             Coverage Diff              @@
##             master       #4      +/-   ##
============================================
+ Coverage     90.32%   95.06%   +4.73%     
- Complexity        8       25      +17     
============================================
  Files             1        9       +8     
  Lines            31       81      +50     
  Branches          0        1       +1     
============================================
+ Hits             28       77      +49     
- Misses            3        4       +1

Impacted Files	Coverage Δ	Complexity Δ
...ceidl/tests/generator/java/JavaGeneratorTest.xtend	100% <100%> (ø)	2 <2> (?)
.../serviceidl/tests/generator/IdlGeneratorTest.xtend	100% <100%> (ø)	1 <1> (?)
.../com/btc/serviceidl/tests/TestExtensionsTest.xtend	100% <100%> (ø)	4 <4> (?)
...sts/generator/protobuf/ProtobufGeneratorTest.xtend	100% <100%> (ø)	2 <2> (?)
...c/com/btc/serviceidl/tests/testdata/TestData.xtend	100% <100%> (ø)	1 <1> (?)
...iceidl/tests/generator/AbstractGeneratorTest.xtend	100% <100%> (ø)	2 <2> (?)
...viceidl/tests/generator/cpp/CppGeneratorTest.xtend	100% <100%> (ø)	2 <2> (?)
.../src/com/btc/serviceidl/tests/TestExtensions.xtend	85.71% <85.71%> (ø)	3 <3> (?)
... and 6 more

---

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 da31433...1d60f94. Read the comment docs.

[sigiesec]

@schregger @huttenlocher Thanks for your suggestions. I will address them in a separate PR, after I reformatted all files.