buildpackages: support CentOS 7.1 and CentOS 7.2

Signed-off-by: Loic Dachary <loic@dachary.org>
(cherry picked from commit 834a38cf90774802c92ba34ae28aab6987a5d4d6)

diff --git a/tasks/buildpackages/centos-7.1-user-data.txt b/tasks/buildpackages/centos-7.1-user-data.txt
new file mode 120000 (symlink)
index 0000000..2eb0e3c
--- /dev/null
+++ b/tasks/buildpackages/centos-7.1-user-data.txt
@@ -0,0 +1 @@
+user-data.txt
\ No newline at end of file

diff --git a/tasks/buildpackages/centos-7.2-user-data.txt b/tasks/buildpackages/centos-7.2-user-data.txt
new file mode 120000 (symlink)
index 0000000..2eb0e3c
--- /dev/null
+++ b/tasks/buildpackages/centos-7.2-user-data.txt
@@ -0,0 +1 @@
+user-data.txt
\ No newline at end of file