Update base images to openwhisk/dockerskeleton:1.3.2. and adjust tests for upstream changes.

Formats all .scala files according to `scalafmt`'s (opinionated) style. 
Adds Travis checks for correctly formatted code.

Using `object`s instead of a hollow class as the "factory" for an Spi makes them being singleton by default, which reduces boilerplate to implement an Spi.

The `Dependencies` object is not used anywhere and there might be better alternatives which we can decide on once the need of them comes up. For now, the Spi's interfaces are relatively tightly coupled to their current default implementations anyway.

Also updated documentation.

- Refactoring the invoker for better encapsulation and separation of concerns in its packages.
- Removing Dispatcher.
- Remove unused properties from the deployment manifests.
- Add error handling for terminal failures

Adds the ability to add pluggable implementations for defined Service Provider Interfaces (SPI). The implementation to load is chosen via configuration.

First set of plug-points are:
- ArtifactStoreProvider
- MessagingProvider

* Add documentation for docker for mac (#1431)
* Replace akka-http client to play-ws client (temporarily)
* Introduce docker-machine environment

* Experimental branch for 2079, uses ibm swift ubuntu image for 3.1

* Fixes issue #2079, add Swift 3.1.1 runtime kind, update Swift dependencies for Watson SDK, KituraNet, SwiftyJson

* add apache license

* Fix swift311 location and catch docker brake

The location of the swift binary for 311 is now in /usr/bin/swift
Need to catch docker errors when building by usig && instead of ;

* new zip for new swift311 runtime

Also fixes bad redirect in build script.

Also, change working directory for Python actions to allow relative path access to file system.

Re-enable build swift/python containers (for tests to run).
Add unicode unit test for swift action container.
Allow for reinit with swift for use with invoke.py.
Fix unicode regression for swift actions.
Refactor unicode tests to add coverage - now also for base action container.
Set string encoding to utf-8 for swift action proxy.
Rewrite result extraction to avoid splitting and printing logs one line at a time.
Skip decoding when process output is a string; already utf-8.

Consolidate base64 encoding in CLI; remove Jar field in exec.

Update tests to work in both Python 2 and Python 3.
Rename pythonaction to python3action for container image name for clarity.
Add tests for python:2 and python:3.
Add image names for all the actions. Rename javaaction to java8action for consistency.

Remove subtypes.

Move exec utils for image construction to singleton.

Rebase

- Remove unused dependencies
- Define dependencies as compile time to be able to include them from other projects
- Standardize layout

* Bumping restassured version

* Update gitignore to include .cache-tests

Add manifest schema.
Add utilities to read Exec runtimes from manifest.
Add runtimes manifest to ansible group vars.
Write out manifest to whisk.properties and make available through WhiskConfig.

The change in #1946 introduced a regression such that it did not allow for Node.js zipped actions which contain an index.js but not a package.json. This is a valid configuration and should be supported.

Using the Windows Explorer method of creating zip actions results in an incorrect zip structure. OW requires that package.json be found at the root of the zip, while the Explorer action insists on putting everything inside a top-level folder inside the zip.

Return an explicit error when package.json is not found at the root of a zipped action.

* Normalize initializer for all execs.

* Handle empty code for blackbox.

* Do not include code if null.

Refactoring of init method into an init-from-source and init-from-zip.
Support a zip file containing more than one python file.
The zip file must contain a file called __main__.py that defines a "main" method.

Log an error when python zip does not include required file.