Support "orbit" package types

[mandrean]

When using rules_jvm_external on a project pulling in an old version of Dropwizard ("io.dropwizard:dropwizard-core:0.7.1",), Bazel fails miserably because one of Dropwizard's declared dependencies in the POM being of package type orbit:

org.eclipse.jetty.orbit:javax.servlet:3.0.0.v201112011016

<groupId>org.eclipse.jetty.orbit</groupId>
<artifactId>javax.servlet</artifactId>
<version>3.0.0.v201112011016</version>
<name>Jetty Orbit :: Servlet API</name>
<description>
This artifact originates from the Orbit Project at Eclipse, it is an osgi bundle and is signed as well.
</description>
<packaging>orbit</packaging>

Fetching/resolving it with the coursier CLI works fine though. Should be an easy fix.

[mandrean]

PR: #117

[jin]

Interesting - the error message for this gets printed 17 times when I add it to an Android project's WORKSPACE file.

Parsed artifact data: {"coord": "org.eclipse.jetty.orbit:javax.servlet:3.0.0.v201112011016", "file": None, "dependencies": []} and referenced by '//java/com/google/android/apps/authenticator:authenticator_lib'
ERROR: Analysis of target '//java/com/google/android/apps/authenticator:authenticator' failed; build aborted: no such package '@maven//': Traceback (most recent call last):
	File "/private/var/tmp/_bazel_jin/01df7c89101fa69de4358628ee7e3155/external/rules_jvm_external/coursier.bzl", line 536
		generate_imports(repository_ctx = repository_ctx, d..., <2 more arguments>)
	File "/private/var/tmp/_bazel_jin/01df7c89101fa69de4358628ee7e3155/external/rules_jvm_external/coursier.bzl", line 335, in generate_imports
		fail(error_message)

The artifact for org.eclipse.jetty.orbit:javax.servlet:3.0.0.v201112011016 was not downloaded. Perhaps its packaging type is
not one of: jar,aar,bundle,eclipse-plugin?

It is also possible that the packaging type of org.eclipse.jetty.orbit:javax.servlet:3.0.0.v201112011016 is specified
incorrectly in the POM file of an artifact that depends on it. For example,
org.eclipse.jetty.orbit:javax.servlet:3.0.0.v201112011016 may be an AAR, but the dependent's POM file specified its `<type>`
value to be a JAR.

The artifact(s) depending on org.eclipse.jetty.orbit:javax.servlet:3.0.0.v201112011016 are:



and their POM files are located at:



---