Remove versions for required packages

Requirement versions were set in the first place to limit the
buginess. However, after some time it appears that it made more
harm than good, as discussed in:
https://review.openstack.org/#/c/388003/

In this commit we remove the versions for all the requirements.

In the future, if a specific dependency version if causing some issue
we should reintroduce the version for this dependency to block the
unstable version.

Sem-Ver: bugfix
Change-Id: Ia42509bf2bf9012cc03c8bb25b84f465425e2aad

packaging/rpm/python-synergy.spec

@@ -17,11 +17,11 @@ Requires(pre):    shadow-utils
 Requires(post):   systemd
 Requires(preun):  systemd
 Requires(postun): systemd
-Requires:         python2-eventlet >= 0.17
-Requires:         python2-oslo-config >= 2.4
-Requires:         python-pbr >= 1.8
-Requires:         python-dateutil >= 2.4
-Requires:         python-requests >= 2.10.0
+Requires:         python2-eventlet
+Requires:         python2-oslo-config
+Requires:         python-pbr
+Requires:         python-dateutil
+Requires:         python-requests
 
 
 %description

requirements.txt

@@ -2,12 +2,12 @@
 # of appearance. Changing the order has an impact on the overall integration
 # process, which may cause wedges in the gate later.
 
-pbr>=1.8,<1.9
+pbr
 
-eventlet>=0.17,<0.18
-oslo.config>=2.4,<2.5
-python-dateutil>=2.2,<2.5
-requests>=2.7.0,<2.11.0
+eventlet
+oslo.config
+python-dateutil
+requests
 
 # Packages not available as system packages (rpm or deb)
-tabulate>=0.7.2,<0.8
+tabulate

setup.py

@@ -23,5 +23,5 @@ except ImportError:
     pass
 
 setuptools.setup(
-    setup_requires=['pbr>=1.8', 'setuptools'],
+    setup_requires=['pbr', 'setuptools'],
     pbr=True)