fix: Fix build in Python 3
fix: Fix build in Python 3

Since Python 3 does not have a separate "unicode" type, we create an
alias to the "str" type for compatibility with Python 2.  We do a type
check against "str" or "unicode" when parsing JSON to locate a node
binary in get_node_binary.

Closes #3102

Change-Id: Ib01fda64865052eed64e35b7856a8c392a319144

shaka-project/shaka-player,shaka-project/shaka-player,tvoli/shaka-player,shaka-project/shaka-player,tvoli/shaka-player,tvoli/shaka-player,shaka-project/shaka-player,tvoli/shaka-player