Sw360

* dependency updates to mitigate potential security vulnerabilities.
* markdown style checks introduced.
* logging introduced, especially to show a warning when adding an attachment
returns is not 201 (created) but 202 (accepted).

* new method `update_project_release_relationship`.
* original get_health_status() endpoint URL has been restored by the SW360 team.
* fix: better check assumptions on returned data, see https://github.com/sw360/sw360python/issues/5.
* `update_project` has a new parameter `add_subprojects` to only **add** the new
sub-projects and not to overwrite all existing sub-projects.

* New method `duplicate_project` to create a copy of an existing project.

* **New Features**:
* `get_projects_by_tag` added.
* `get_releases_by_name` added.
* `get_all_vendors` added.
* We have covered nearly all of the possible REST API calls.
The library is successfully being used by multiple projects.
Time to release version 1.0.0.

* **New Features**:
* support to retrieve information about clearing requests (`get_clearing_request`,
`get_clearing_request_for_project`).

* relicensed to MIT.
* **Breaking API changes**:
* create_new_{component,release,project} now have parameters for required attributes
* drop support for dump_rest_call() and dump_rest_call_to_file().
* upload_attachment() has been renamed to upload_release_attachment(). This is to have
the same naming scheme for the new methods upload_component_attachment() and
upload_project_attachment().
* **New Features**:
* support of the group parameter for the /projects endpoint.
* SW360 REST API now support project fields 'Project state' and 'Phase-out since'.
* get_health_status() added.
* get_project_vulnerabilities() added.
* SW360Error has new property `details`.
* **Improvements**:
* Debug option to suppress session handling.
* unit tests added.
* published on GitHub.