Upgrade dependencies

Merge pull request #4 from esl/export-config-type

Export useful type 'config/0'

We can use this type in mongoose_shaper.

Merge pull request #3 from esl/peek_available

Peek available

Merge pull request #1 from esl/support_other_units

Support other units

Merge pull request #2 from NelsonVides/improvements

Improvements

Accept floats in config

Fix documentation

Add README