(fix): added unit tests for leaf node parsing

[thomaszurkan-optimizely]

Summary

• After adding some compatibility tests, we discovered there were some errors in single leaf processing. Fixed those and added tests.

Test plan

Added unit tests in all json parsers for single leaf parsing.
Added a single leaf node in the datafile and have all parsers parse it the same.

Issues

• Java SDK was failing compatibility tests.

[coveralls]

Pull Request Test Coverage Report for Build 766

• 17 of 18 (94.44%) changed or added relevant lines in 2 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.1%) to 89.86%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
core-api/src/main/java/com/optimizely/ab/config/parser/ConditionJacksonDeserializer.java	16	17	94.12%

Totals
Change from base Build 765:	0.1%
Covered Lines:	2694
Relevant Lines:	2998

---

💛 - Coveralls

[coveralls]

Pull Request Test Coverage Report for Build 769

• 15 of 16 (93.75%) changed or added relevant lines in 3 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.2%) to 89.947%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
core-api/src/main/java/com/optimizely/ab/config/parser/ConditionJacksonDeserializer.java	13	14	92.86%

Totals
Change from base Build 765:	0.2%
Covered Lines:	2693
Relevant Lines:	2994

---

💛 - Coveralls

[nchilada]

So fast! Thanks! Might be good to run the compatibility test against this if you know how (I don't 😬)

[nchilada]

The compat test now passes! Thanks @thomaszurkan-optimizely 😊