* test: add test case

* feat: add chart tooltip in histogram overlay

* feat: add tooltip in histogram chart

* Add pr curve.

* chore: update dependencies

* fix: compatibility of safari (#674)

* chore: code polishment

* fix: calculate step width in tooltip (#672)

* doc: update readme

* feat: histogram

* Fix warning for hdfs

* Update docs.

* fix: graph export style missing

* bump 2.0.0-beta.6

* build: use stable channel of rust toolchain

* feat: support model graph from backend

* feat: add filename in graph api

* feat: support api token key in visualdl service

* Add --model to parameters.

* Add histogram, add hdfs.

* build: update travis-ci configuration

* fix: public path error in graphs page

* chore: update dependencies

* feat: high-dimensional chart will fit screen size now

* fix: scatter chart cannot be rendered properly

* chore: separate api module

* intergrate netron

* intergrate netron

* feat: graphs

* style: fix lint

* chore: update dependencies

* fix: type error

* chore: update dependencies

* chore: update graph color

changes made:
1. adjusted path to relative path
2. added an installation method (installing by coding)
Co-authored-by: NZeyu Chen <chenzeyu01@baidu.com>

* fix: public path cannot be set to root path if not in api mode

* fix: use position argument

* fix: support legacy call method

* doc: update document