* Enforce not using Maven 3.6.2

* Use Maven 3.6.3 via Maven wrapper for Travis

Closes #1118
Closes #1165

Co-authored-by: Sergey Puchnin <spuchnin@gridgain.com>
Co-authored-by: Taras Ledkov <tledkov@gridgain.com>
Co-authored-by: Oleg Ostanin <oostanin@gridagin.com>

* [core] Drop JDK 7 Support

Sets compiler target to 1.8
Additionally removes openjdk7 from travis build-matrix
Fixes #1033

Additionally includes lexicographic reordering of binding-dependency properties in root pom

* [core] introduce baseclass for timeseries database bindings

This base-class parses the queries generated by TimeSeriesWorkload into a format
that's usable for simple consumption.
The format has been defined through the work done by Andreas Bader (@baderas) in
https://github.com/TSDBBench/YCSB-TS.

* [core] parse debug and test properties for all Timeseries databases

* [core] Add method to define possible tagKeys for Timeseries Workloads

Some TimeSeries Databases require a "schema" up front.
To generate said schema, the tag keys used by the workload are required.
This method should be centrally available for maintainability

* [core] Provide default implementation for  operation

TimeSeries databases only rarely support deleting data. As such we can generally assume
the operation to always return a Status.NOT_IMPLEMENTED. Similarly to updating that trivial
implementation does not need to be repeated in every TimeSeriesDatabase implementation

* [core] Address review

This adds a copyright header and significant amounts of javadoc for TimeseriesDB
Furthermore occurrences of Long have been largely replaced with the primitive long
Finally an overload for signed integer values has been added for insertions

[accumulo, accumulo1.6, accumulo1.7, accumulo1.8] switch Accumulo to minor version specific bindings.

* break out accumulo modules
* add deprecation warning
* switch travis to use short hostname to get around long hostname error.

* Add oraclejdk9 to .travis.yml

* Upgrade maven-compiler-plugin

* Exclude jdk.tools from hadoop dependency

* Set minimum maven version to 3.1.0+, due to reqs for ES testing
* remove oracle jdk7 per travis-ci/travis-ci#7884
* Skip ES5 cluster spin-up if tests are skipped.
* Increase test heap for asynchbase binding from Travis 2048m to 4096m
  - https://docs.travis-ci.com/user/build-environment-updates/2017-09-06/
* temporarily remove the riak service on travis
  - currently fails w/o details
  - http://docs.basho.com/ fails to load, so I can't spin up a test node locally.

* in couchbase2 work around ReactiveX/RxJava#3824
* accumulo test hangs, so skip tests
* hbase10 and asynchbase test crashes with unknown class version, so skip tests
* orientdb tests fail, so skip
* core jar-with-deps fails, so keep them broken out

fixes #704, fixes #705

[riak] Configured RiakKVClientTest.java to work with default bucket-type instead of creating a new one.

[travis] Added riak-admin commands to create and activate test bucket.

[riak] Added test unit.
[riak] Set eventual consistency as default in both README.md and riak.properties file, as strong consistency it's not the main model adopted by the db (check http://docs.basho.com/riak/kv/2.1.4/developing/app-guide/strong-consistency/ for further info).
[riak] Fixed getFields() function by transforming it into createResultHashMap(). This function creates the HashMap to give as result appropriately.
[riak] Removed scan transaction support for strong consistency model. 2i search is not allowed for this model, neither there is a suitable search mean to use to achieve a proper scan transaction.
[riak] Done minor fixes to code and comments.

Fixes #438

[travis] Fixes #389 - Update .travis.yml to use the container based infrastructure for Travis Builds.