Update requirements without versions

requirements.txt

@@ -1,22 +1,7 @@
-asn1crypto==0.24.0
-attrs==19.1.0
-Automat==0.7.0
-cffi==1.12.3
-constantly==15.1.0
-cryptography==2.7
-csiphash==0.0.5
-hyperlink==19.0.0
-idna==2.8
-incremental==17.5.0
-numpy==1.17.2
-pyasn1==0.4.6
-pyasn1-modules==0.2.6
-pycparser==2.19
-PyHamcrest==1.9.0
-pyOpenSSL==19.0.0
-PyYAML==5.1.2
-redis==3.3.8
-service-identity==18.1.0
-six==1.12.0
-Twisted==19.7.0
-zope.interface==4.6.0
+twisted
+pyOpenSSL
+redis
+pyYaML
+python-logstash
+service_identity
+csiphash