Plugin version error in scenario test for vanilla2.6.0

As 2.6.0 is deprecated, this file can be removed.

Change-Id: Id7b238978ae63b1fc95da8c34455784091ec9e66
Closes-bug: 1514322

etc/scenario/sahara-ci/vanilla-2.6.0.yaml.mako

@@ -1,90 +0,0 @@
-clusters:
-  - plugin_name: vanilla
-    plugin_version: 2.7.1
-    image: ${vanilla_two_six_image}
-    node_group_templates:
-      - name: worker-dn-nm
-        flavor: ${ci_flavor_id}
-        node_processes:
-          - datanode
-          - nodemanager
-        volumes_per_node: 2
-        volumes_size: 2
-        auto_security_group: true
-        node_configs:
-          &ng_configs
-          MapReduce:
-            yarn.app.mapreduce.am.resource.mb: 256
-            yarn.app.mapreduce.am.command-opts: -Xmx256m
-          YARN:
-            yarn.scheduler.minimum-allocation-mb: 256
-            yarn.scheduler.maximum-allocation-mb: 1024
-            yarn.nodemanager.vmem-check-enabled: false
-      - name: worker-nm
-        flavor: ${ci_flavor_id}
-        node_processes:
-          - nodemanager
-        auto_security_group: true
-        node_configs:
-          *ng_configs
-      - name: worker-dn
-        flavor: ${ci_flavor_id}
-        node_processes:
-          - datanode
-        volumes_per_node: 2
-        volumes_size: 2
-        auto_security_group: true
-        node_configs:
-          *ng_configs
-      - name: master-rm-nn-hvs
-        flavor: ${ci_flavor_id}
-        node_processes:
-          - namenode
-          - resourcemanager
-          - hiveserver
-        auto_security_group: true
-        node_configs:
-          *ng_configs
-      - name: master-oo-hs-sn
-        flavor: ${ci_flavor_id}
-        node_processes:
-          - oozie
-          - historyserver
-          - secondarynamenode
-        auto_security_group: true
-        node_configs:
-          *ng_configs
-    cluster_template:
-      name: vanilla271
-      node_group_templates:
-        master-rm-nn-hvs: 1
-        master-oo-hs-sn: 1
-        worker-dn-nm: 2
-        worker-dn: 1
-        worker-nm: 1
-      cluster_configs:
-        HDFS:
-          dfs.replication: 1
-    cluster:
-      name: ${cluster_name}
-    scaling:
-      - operation: resize
-        node_group: worker-dn-nm
-        size: 1
-      - operation: resize
-        node_group: worker-dn
-        size: 0
-      - operation: resize
-        node_group: worker-nm
-        size: 0
-      - operation: add
-        node_group: worker-dn
-        size: 1
-      - operation: add
-        node_group: worker-nm
-        size: 1
-    edp_jobs_flow:
-      - pig_job
-      - mapreduce_job
-      - mapreduce_streaming_job
-      - java_job