For #27: Update documentation re: npm version.
Merge pull request #28 from dougborg/documentation_updates

For #27: Update documentation re: npm version.
Fix #29: Add `npmVersion` to `node` extension.

 - This is implemented as a special NpmTask that installs npm at the
   version specified by `npmVersion` in the `node {}` configuration
   closure.
 - The `setupNpm` task will be skipped if `npmVersion` is not set,
   and works independently of the `download` or `version` options.
 For #29: Update documenation for npmVersion.
Use dependsOn rather than setDependsOn.
Merge pull request #30 from dougborg/npm_setup

Fix #29: Add `npmVersion` to `node` extension.
Update CHANGELOG.md
Upgraded to Gradle 2.1 for wrapper.
Released version 0.7
Updated to next version
Fix #34: Add node to path for NodeExec.

 - Prepend the node bin directory to the `PATH` in the NodeExecRunner
   for downloaded / managed node installations.
Merge pull request #35 from dougborg/add_node_to_path

Fix #34: Add node to path for NodeExec.
Update CHANGELOG.md
For #36: Publish snapshots to jcenter.

 - Still needs encrypted `BINTRAY_USER` and `BINTRAY_KEY` added to the
   `.travis.yml` file.
Add artifactory plugin.

 - Consolidate plugin declarations into the new `plugins {}` closure.
 - Also add the `java-gradle-plugin` which is supposedly handy for
   gradle plugins.
Added encrypted values for BINTRAY_USER and BINTRAY_KEY
Merge branch 'publish_snapshots' of github.com:dougborg/gradle-node-plugin into dougborg-publish_snapshots

Conflicts:
	.travis.yml
Merge branch 'publish_snapshots' of github.com:dougborg/gradle-node-plugin into dougborg-publish_snapshots

Conflicts:
	.travis.yml
Merge branch 'dougborg-publish_snapshots'
Added artifactory snapshot repo url.