Clean up #1271

[orenyk]

Due to my trigger-happy fingers, I merged #1297 pre-review. We should do some final tweaks and write specs for both fixes in #1271 (the spaces in headers and the invalid character parsing) to ensure that everything's working as expected. Sorry!

To Do:

• fix extra spaces in error message
• double check instructions for spaces in example CSV
• double check that UTF-8 encoding command is actually happening
• write specs for both header spaces and UTF-8 invalid character parsing
• switch checking for whitespace and raising an error with just parsing out any whitespace in the header row

[orenyk]

Just left some inline comments in #1297, refer to those for feedback. Thanks!

[orenyk]

Based on the last set of comments in #1297, I've added the parsing of whitespace out and removing the error message we just added to the to-do list above.