Log failing SQL to file

[DylanBaker]

closes #84

This PR grabs the sql variable on the SqlError and logs the query to the logs and to a file in the logs directory.

Initially, I wrote it that the log_failing_sql function didn't take a directory, and just used the LOG_DIRECTORY global variable. I was having some difficulty getting the tests to work though as I couldn't seem to overwrite that variable and log the queries to a temp directory. Very open to feedback/advise on how to improve that.

[codecov]

Codecov Report

Merging #179 into master will decrease coverage by 0.04%.
The diff coverage is 58.33%.

@@            Coverage Diff             @@
##           master     #179      +/-   ##
==========================================
- Coverage   70.70%   70.66%   -0.05%     
==========================================
  Files          10       10              
  Lines         809      818       +9     
==========================================
+ Hits          572      578       +6     
- Misses        237      240       +3     

Impacted Files	Coverage Δ
spectacles/logger.py	57.69% <42.85%> (-22.31%)	⬇️
spectacles/cli.py	72.66% <80.00%> (+3.15%)	⬆️

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