Add ability to skip tests against specific ES versions (attribute based)
Skip TermVector invalid id tests on ES 1.2 (https://github.com/elasticsearch/elasticsearch/issues/6451)
Fix DocAsUpsert test: id was not specified
Skip RootPropertiesShouldSerialize test on ES 1.2.0 (https://github.com/elasticsearch/elasticsearch/pull/6353)
Remove unnecessary/bad index call that causes test to hang on 1.1.2
Manually map histogram aggregation item to support ES 1.2 response as well as 1.1 and 1.0
Skip tests for aggregations that don't exist in ES 1.0
currentVersion field should be private
Skip alias during index creation test in 1.0 (wasn't added until 1.1)
Fix alias tests failing on 1.0 due to trying to add aliases during index creation
Fix histogram item mapping for ES 1.2
Skip ClearScroll test for ES 1.0.2
Create cache folder if it doesn't exist
Better way of getting the current running ES version
Merge branch 'develop' into feature/improve-tests
Bump yaml tests to 1.2.1
Merge pull request #751 from elasticsearch/feature/improve-tests

Feature/improve tests