Update trafilatura requirement from <1.7,>=1.4 to >=1.4,<1.8

Updates the requirements on [trafilatura](https://github.com/adbar/trafilatura) to permit the latest version.
- [Release notes](https://github.com/adbar/trafilatura/releases)
- [Changelog](https://github.com/adbar/trafilatura/blob/master/HISTORY.md)
- [Commits](adbar/trafilatura@v1.4.0...v1.7.0)

---
updated-dependencies:
- dependency-name: trafilatura
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

setup.py

@@ -14,7 +14,7 @@
     "py3langid==0.2.*",
     # various content extractors we try to use
     "newspaper3k==0.2.*", "goose3==3.1.*", "BeautifulSoup4>=4.11,<4.13", "readability-lxml==0.8.*",
-    "trafilatura>=1.4,<1.7", "boilerpy3==1.0.*",
+    "trafilatura>=1.4,<1.8", "boilerpy3==1.0.*",
     # support
     "requests",         # leave un-versioned so dependencies can sort of which version is best
     "faust-cchardet==2.1.*",  # BeautifulSoup4 speedup