Test codecs linux (#701)
Test codecs linux (#701)

* Make test_codecs passing with CPython 3.4 on Linux

* Make test_codecs passing with CPython 3.4 on macOS

* Revert "Make test_codecs passing with CPython 3.4 on macOS"

This reverts commit e6a53913ce0677fd726394fa1adb17f43eaa1907.

* Use is_linux iso is_posix for Linux-specific condition in test_codecs

IronLanguages/ironpython3,IronLanguages/ironpython3,IronLanguages/ironpython3,IronLanguages/ironpython3,IronLanguages/ironpython3,IronLanguages/ironpython3