Fix Metric.update and add snippets for Metric class#1221

Merged

mziccard merged 3 commits intogoogleapis:masterfrom mziccard:metric-snippets

Sep 2, 2016

+303-22

Commits on Sep 1, 2016

Remove unnecessary MetricInfo parameter for Metric.update(Async)
mziccard
committed
Update snippets script to support final method parameters
mziccard
committed
Add snippets to Metric's javadoc, MetricSnippets class and tests
mziccard
committed