Pass more information in user defined parse error

Remove wasm warnings

Trial to improve travis config.

…-docs

Add git information in sys and platform modules.

Update documentation folder and readme.

… vm.

Enable clippy in CI

parser error handling improvements.

Improve f-string syntax. Fixes #1099

make exceptions repr tests Python 3.7-friendly by eval-repr round-trip

Improve tests for int ratio properties

stdlib.io: Implement seekable()

Add some extra profiling trace points.

PySliceableSequence trait methods require Range<usize>
as arguments

Allow stdlib freeze

Write bytecode

Implement str iterator support

* Add empty tuple optimization

* Add test snippet for empty tuple

freeze stdlib in WASM

Add an example usecase of the parser.

Add frozen package support

Use cargo-sweep to manage travis caches