tests: refact ci testing master

We should test ceph-ansible against the latest ansible stable version on
master.

This commit also remove the pinning to 1.7.1 version of testinfra
because ansible 2.5 requires a newer version.

Signed-off-by: Guillaume Abrioux <gabrioux@redhat.com>

tests/requirements.txt

@@ -1,4 +1,7 @@
 # These are Python requirements needed to run the functional tests
-testinfra==1.6.0
+testinfra
 pytest-xdist
+pytest==3.6.1
 notario>=0.0.13
+ansible~=2.5,<2.6
+netaddr

tests/requirements2.4.txt

@@ -1,6 +0,0 @@
-# These are Python requirements needed to run the functional tests
-# testinfra < 1.7.1 does not work Ansible 2.4, see https://github.com/philpep/testinfra/issues/249
-testinfra==1.7.1
-pytest-xdist
-pytest==3.6.1
-notario>=0.0.13

tests/requirements2.5.txt

@@ -1 +0,0 @@
-requirements2.4.txt

tox.ini

@@ -160,16 +160,7 @@ setenv=
   luminous: UPDATE_CEPH_DOCKER_IMAGE_TAG = latest
   lvm_osds: CEPH_STABLE_RELEASE = luminous
   bluestore_lvm_osds: CEPH_STABLE_RELEASE = luminous
-deps=
-  ansible2.2: ansible==2.2.3
-  ansible2.2: -r{toxinidir}/tests/requirements2.2.txt
-  ansible2.3: ansible==2.3.1
-  ansible2.3: -r{toxinidir}/tests/requirements2.2.txt
-  ansible2.4: ansible~=2.4,<2.5
-  ansible2.4: -r{toxinidir}/tests/requirements2.4.txt
-  ansible2.5: ansible~=2.5,<2.6
-  ansible2.5: -r{toxinidir}/tests/requirements2.5.txt
-  ooo_collocation: netaddr
+deps= -r{toxinidir}/tests/requirements.txt
 changedir=
   # tests a 1 mon, 1 osd, 1 mds and 1 rgw xenial cluster using non-collocated OSD scenario
   xenial_cluster: {toxinidir}/tests/functional/ubuntu/16.04/cluster