localIP: try resolving local hostname first

[tudor]

Fixes #129.

Signed-off-by: Tudor Bosman tudor@rockset.com

Which problem is this PR solving?

• The C++ Jaeger client always populates the "ip" tag with 127.0.0.1 #129

Short description of the changes

• Just like the Jaeger Java client does, resolve the local hostname in order to determine the local IP address (to populate the "ip" tracer tag with).

[tudor]

The test failure seems unrelated:

[ RUN      ]Reporter.testRemoteReporter
/home/travis/build/jaegertracing/jaeger-client-cpp/src/jaegertracing/reporters/ReporterTest.cpp:80: Failure
Expected equality of these values:
  i + 1
    Which is: 72
  spans.size()
    Which is: 71
[  FAILED  ]Reporter.testRemoteReporter (333 ms)

[isaachier]

One small change please.

[tudor]

Updated to catch (...). PTAL?

[isaachier]

LGTM. Thanks!