Bump joblib from 0.12.0 to 1.2.0

Bumps [joblib](https://github.com/joblib/joblib) from 0.12.0 to 1.2.0.
- [Release notes](https://github.com/joblib/joblib/releases)
- [Changelog](https://github.com/joblib/joblib/blob/master/CHANGES.rst)
- [Commits](https://github.com/joblib/joblib/compare/0.12...1.2.0)

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

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

requirements.txt

@@ -1,9 +1,9 @@
 gym[mujoco,atari,classic_control,robotics]
 demjson==2.2.4
-joblib==0.12.0
+joblib==1.2.0
 pandas==0.22.0
 matplotlib==3.0.2
-joblib==0.12.0
+joblib==1.2.0
 tensorflow_gpu==1.15.2
 cloudpickle==0.5.3
 opencv_python==3.4.0.12