Fixed not working --output option

[r-plus]

Fixed --output option is not working correctly. --output option passed as output option, but JSONReporter required output_path option.

This is not breaking change to users that using JSONReporter from ruby. I also make breaking change version of branch https://github.com/r-plus/xcprofiler/commit/d9877238d5c4e12acc235fc07efd94d0ea0cd8e2 that rename to output from output_path which do you like?

$ ./bin/xcprofiler spec/fixtures/MyApp-xxxxxxxxxxx/Logs/Build/valid.xcactivitylog -l 1 -t 10 --output hoge.json
+-------------------+------+-------------+----------+
| File              | Line | Method name | Time(ms) |
+-------------------+------+-------------+----------+
| Interaction.swift | 17   | get {}      | 69.9     |
+-------------------+------+-------------+----------+
[JSONReporter] output_path is not specified