Server infrastructure: switch default URLs to HTTPS

HTTPS has been enabled on the avocado-project.org server, so let's use
it by default on docs and when downloading images from it.
Signed-off-by: NCleber Rosa <crosa@redhat.com>

README.rst

@@ -104,7 +104,7 @@ Term Stability) releases available from its own package repository.
 To use it, first get the package repositories configuration file by
 running the following command::
 
-    sudo curl http://avocado-project.org/data/repos/avocado-fedora.repo -o /etc/yum.repos.d/avocado.repo
+    sudo curl https://avocado-project.org/data/repos/avocado-fedora.repo -o /etc/yum.repos.d/avocado.repo
 
 Now check if you have the ``avocado`` and ``avocado-lts`` repositories configured by running::
 
@@ -149,11 +149,11 @@ following command should do it::
     yum install https://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm
 
 Then you must use the Avocado project RHEL repo
-(http://avocado-project.org/data/repos/avocado-el.repo).
+(https://avocado-project.org/data/repos/avocado-el.repo).
 Running the following command should give you the basic Avocado
 installation ready::
 
-    curl http://avocado-project.org/data/repos/avocado-el.repo -o /etc/yum.repos.d/avocado.repo
+    curl https://avocado-project.org/data/repos/avocado-el.repo -o /etc/yum.repos.d/avocado.repo
     yum install python-avocado
 
 Other available packages (depending on the Avocado version) may include:

avocado/utils/vmimage.py

@@ -240,7 +240,7 @@ class JeosImageProvider(ImageProviderBase):
             arch = '64'
 
         super(JeosImageProvider, self).__init__(version, build, arch)
-        self.url_versions = 'http://avocado-project.org/data/assets/jeos/'
+        self.url_versions = 'https://avocado-project.org/data/assets/jeos/'
         self.url_images = self.url_versions + '{version}/'
         self.image_pattern = 'jeos-{version}-{arch}.qcow2.xz$'
 

docs/source/GetStartedGuide.rst

@@ -91,7 +91,7 @@ Term Stability) releases available from its own package repository.
 To use it, first get the package repositories configuration file by
 running the following command::
 
-    sudo curl http://avocado-project.org/data/repos/avocado-fedora.repo -o /etc/yum.repos.d/avocado.repo
+    sudo curl https://avocado-project.org/data/repos/avocado-fedora.repo -o /etc/yum.repos.d/avocado.repo
 
 Now check if you have the ``avocado`` and ``avocado-lts`` repositories configured by running::
 
@@ -134,11 +134,11 @@ following command should do it::
     yum install https://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm
 
 Then you must use the Avocado project RHEL repo
-(http://avocado-project.org/data/repos/avocado-el.repo).
+(https://avocado-project.org/data/repos/avocado-el.repo).
 Running the following command should give you the basic Avocado
 installation ready::
 
-    curl http://avocado-project.org/data/repos/avocado-el.repo -o /etc/yum.repos.d/avocado.repo
+    curl https://avocado-project.org/data/repos/avocado-el.repo -o /etc/yum.repos.d/avocado.repo
     yum install python-avocado
 
 Other available packages (depending on the Avocado version) may include: