add more test cases for lambda tokenization

fix lambda parsing issues #246

These are type stub files for PEP 484.

Not all docstrings are SQL

Add missing sql scope to single-quoted single-line SQL strings

Inject Python string patterns into embedded SQL strings

Improve tokenization

Tokenize function and parameter annotations

It's a bit too complicated to do now with annotations in the mix.

Tokenize binary strings

PEP-3112

Tokenize async function definitions

* Consolidate missing parameter tokenization

PEP-492

Improve lambda tokenization

Fixes #56

Tokenize `yield from`

PEP-380

Add support for f-strings and nested replacement fields

Do not recursively match character classes

Tokenize {{ and }} as escape characters

Level up string formatting

If it turns out people want it it'll be trivial to add

Use Trusty on Travis

Clean up function calls

Add tree-sitter Python grammar

Extend Snakemake support

Lowercase hex in str

Async indent

Remove patterns for decreasing next indent level