Add payload truncation strategies.
Clone payload just once in StringsStrategy.
Return the last truncation result if all of them fail and log it correctly.
Return nil on #dump_payload if couldn't be truncated.
Remove unneeded trace_key variable in MinBodyStrategy.
Remove unneeded trace_key variable in StringsStrategy.
Replace return statement with break in StringsStrategy.
Add payload fixtures and helpers to load them.
Add helper to load and parse json payloads.
Add specs for FramesStrategy.
Add specs for MinBodyStrategy.
Add specs for StringsStrategy.
Add # encoding head for StringsStrategy specs file.
Replace deep_symbolize_keys calls with own implemenetation, symbolize_recursive.
Add specs for Rollbar::Truncation.
Merge pull request #185 from rollbar/smart-truncation

Smart truncation