Merge branch 'release/0.3.0' into develop
Create a TunnelMonoid
Create IncrementingTunnelMonoid, update comments
Combine TunnelMonoid and IncrementingTunnelMonoid work
Refactor common tests
Get rid of deprecated call
Override isNonZero, minor comment tweak
Add license header
Rename IncrementingTunnelMonoid to PromiseLinkMonoid, fix minor issues
Merge pull request #213 from jcoveney/jco/tunnel_monoid

Create TunnelMonoid and IncrementingTunnelMonoid to allow hooking into async monoid computation
Use Await
Properly use Await
Merge pull request #212 from jcoveney/jco/update_util_algebra

Get rid of deprecated Future call in UtilAlgebraProperties
Add accessors for DecayValue's value
Remove valueNow, move epsilon to arguments, and formatting
Move valueAsOf into monoid
make decayed value monoid a separate class
Merge pull request #223 from tsdeng/separate_decayed_value_monoid

Separate decayed value monoid
SketchMap#create improvements
Merge pull request #227 from andrewnguyen/andrewnguyen/algebird225

SketchMap#create improvements