Merge branch 'release/0.3.8' into develop
Change travis to only test the `test` directory
Add docstrings for new functions and _DynamicResizableListBuilder
Fix docstring typo in PackedFdMessageReader
Change load to use a global SchemaParser. Make structs settable as field
Add forgotten test files
Fix up docs for new C++ RC
Bump version for v0.3.9
Merge branch 'release/0.3.9'