WIP Implement Java SDK to send traces and create an example app

[IridiumOxide]

Closes: GH-5
Closes: GH-6

---

This change is 

[kwapik]

If supporting of Java 8 is much of a problem, just drop it. We can support Java > 11 for start.

Reviewed 8 of 8 files at r1, all commit messages.
Reviewable status: all files reviewed, 1 unresolved discussion (waiting on @IridiumOxide)

---

src/main/java/com/fluxninja/aperture/example/App.java line 22 at r1 (raw file):

    public static void main(String[] args) {
        final String agentHost = "aperture-agent.aperture-system.svc.cluster.local";

NIT: You can change this to match playground deployment i.e. aperture-agent.aperture-agent.svc.cluster.local

---

src/main/java/com/fluxninja/aperture/sdk/ApertureSDK.java line 67 at r1 (raw file):

    // TODO: find a way to get ip from header
    String ip = "192.168.0.1";

After reading our collector code - the feature_ip label is not requiread anymore, so you can scrape the whole IP thing.

[kwapik]

Reviewed 7 of 7 files at r2, all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @IridiumOxide)