[test] testSimpleWorkflow() and testListBlobs_26() use same snapshot name

`testSimpleWorkflow()` and `testListBlobs_26()` use same `test-snap` snapshot name.

So we might get this issue:

```
2015-04-29 12:02:47,279 WARN  snapshots - [node_s0] failed to create snapshot [test-repo:test-snap]
InvalidSnapshotNameException[[test-repo:test-snap] Invalid snapshot name [test-snap], snapshot with such name already exists]
	at org.elasticsearch.repositories.blobstore.BlobStoreRepository.initializeSnapshot(BlobStoreRepository.java:228)
	at org.elasticsearch.repositories.azure.AzureRepository.initializeSnapshot(AzureRepository.java:148)
	at org.elasticsearch.snapshots.SnapshotsService.beginSnapshot(SnapshotsService.java:303)
	at org.elasticsearch.snapshots.SnapshotsService.access$500(SnapshotsService.java:88)
	at org.elasticsearch.snapshots.SnapshotsService$1$1.run(SnapshotsService.java:229)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
	at java.lang.Thread.run(Thread.java:745)
```

Closes #85.
(cherry picked from commit 9925604)
(cherry picked from commit 409fd1e)

Author: dadoonet

src/test/java/org/elasticsearch/repositories/azure/AzureSnapshotRestoreITest.java

@@ -272,14 +272,14 @@ public void testListBlobs_26() throws StorageException, URISyntaxException {
         assertThat(client.prepareGetSnapshots("test-repo").get().getSnapshots().size(), equalTo(0));
 
         logger.info("--> snapshot");
-        CreateSnapshotResponse createSnapshotResponse = client.prepareCreateSnapshot("test-repo", "test-snap").setWaitForCompletion(true).setIndices("test-idx-*").get();
+        CreateSnapshotResponse createSnapshotResponse = client.prepareCreateSnapshot("test-repo", "test-snap-26").setWaitForCompletion(true).setIndices("test-idx-*").get();
         assertThat(createSnapshotResponse.getSnapshotInfo().successfulShards(), greaterThan(0));
 
         // Get all snapshots - should have one
         assertThat(client.prepareGetSnapshots("test-repo").get().getSnapshots().size(), equalTo(1));
 
         // Clean the snapshot
-        client.prepareDeleteSnapshot("test-repo", "test-snap").get();
+        client.prepareDeleteSnapshot("test-repo", "test-snap-26").get();
         client.prepareDeleteRepository("test-repo").get();
 
         logger.info("-->  creating azure repository path [{}]", getRepositoryPath());
@@ -294,7 +294,7 @@ public void testListBlobs_26() throws StorageException, URISyntaxException {
         assertThat(client.prepareGetSnapshots("test-repo").get().getSnapshots().size(), equalTo(0));
 
         logger.info("--> snapshot");
-        createSnapshotResponse = client.prepareCreateSnapshot("test-repo", "test-snap").setWaitForCompletion(true).setIndices("test-idx-*").get();
+        createSnapshotResponse = client.prepareCreateSnapshot("test-repo", "test-snap-26").setWaitForCompletion(true).setIndices("test-idx-*").get();
         assertThat(createSnapshotResponse.getSnapshotInfo().successfulShards(), greaterThan(0));
 
         // Get all snapshots - should have one