Bump django-compressor from 2.2 to 2.4

Bumps [django-compressor](https://github.com/django-compressor/django-compressor) from 2.2 to 2.4.
- [Release notes](https://github.com/django-compressor/django-compressor/releases)
- [Changelog](https://github.com/django-compressor/django-compressor/blob/develop/docs/changelog.txt)
- [Commits](https://github.com/django-compressor/django-compressor/commits)

Signed-off-by: dependabot-preview[bot] <[email protected]>

Author: dependabot-preview[bot]

requirements.txt

@@ -7,19 +7,20 @@
 certifi==2018.11.29       # via requests
 chardet==3.0.4            # via requests
 django-amber==0.8.0
-django-appconf==1.0.2     # via django-compressor
+django-appconf==1.0.3     # via django-compressor
 django-dotenv==1.4.2
 django-markdown-deux==1.0.5
 django==1.10.4
-django_compressor==2.2
+django_compressor==2.4
 http-crawler==0.1.2       # via django-amber
 idna==2.8                 # via requests
 lxml==3.7.1               # via http-crawler
 markdown2==2.3.7          # via django-markdown-deux
 pyyaml==3.12              # via django-amber
 rcssmin==1.0.6            # via django-compressor
 requests==2.21.0
-rjsmin==1.0.12            # via django-compressor
+rjsmin==1.1.0             # via django-compressor
+six==1.13.0               # via django-appconf, django-compressor
 tinycss2==0.5             # via http-crawler
 urllib3==1.24.1           # via requests
 webencodings==0.5         # via tinycss2