chore(benchmark): add underscorejs lib
feat(benchmark): add ability to profile memory usage per iteration
chore(benchmark): reduce code duplication with updateTimes()
chore(travis.yml): enable g3v1x, disable g3v1x-master
fix(scope): remove deprecation warning for scope.watch with context

This was added in e8a5ce734b00fd22f700e2fc1be5507dda195638.
We will be looking into this some more.
chore(benchmark): remove test for generateReportPartial
feat(benchmark): add statistical functions to calculate confidence interval
feat(benchmark): add confidence and stability info to averages
feat(benchmark): calculate relative margin of error and simplify report
fix(benchmark): fix standard deviation calculation

Previous algorithm was dividing total of squares by sample length,
where it should have been dividing by sample length minus 1
feat(benchmark): add standard deviation to report
chore(benchmark): remove interpolateHtml method
chore(benchmark): remove redundant getAverages method
refactor(benchmark): move all methods/props to appropriate namespaces
fix(WatchGroup): Handle watching elements of array that were removed.

Closes #1046
feat(Scope): Instrument Scope to use User tags in Dart Obervatory

Closes #1138
feat(benchmark): calculate coefficient of variation
refactor(benchmark): reduce complexity, and move formatting of values into template
refactor(benchmark): reduce code redundancy for statistics calculations
feat(benchmark): improve layout of data by moving averages to dedicated row