v0.6.7

Commits

• 64cd25e: sketch out documentation (#129) (Vincent Sarago) #129
• e72a17c: Update README.md (#130) (Vincent Sarago) #130
• 189c17b: Correct insert_mode check (#135) (Anthony Lukach) #135
• 5669749: Keep pypgstac compatible with Python 3.7 (#132) (Denis Rykov) #132
• 2ef0269: Fix prev when reading first token_type=prev (#141) (Alvaro Huarte) #141