Encoding not declared correctly in agent.py

[aph3rson]

When calling _get_agent_source(), the compiled agent is opened with open(). However, the encoding isn't declared in this call properly - therefore, it will use the operating system default to open the file. On some systems, this will likely default to utf-8 or similar - however, Windows systems will still open files as cp1252 (see this StackOverflow thread). The agent.js file appears to contain some characters, such as 0x81 which are invalid in cp1252 (as to why, I'm unsure).

Reformatting agent.js in ANSI seems to fix this issue - however, I think the easier option would be to add encoding='utf-8 to the open() call, as this is the standard method of doing so.

[aph3rson]

I can file a PR, if that's necessary.

[leonjza]

Thanks for the debugging work on this! Feel free to do a PR if you have time, otherwise, I should be able to get to this later tonight and push a new release. 👍

[aph3rson]

#192 will fix this issue.