v1.8.1

Rocket v1.8.1

Diff since v1.8.0

Merged pull requests:

• Fix async pairwise (#54) (@bvdmitri)

Closed issues:

• Pairwise fails with asynchronous inputs (#43)
• timer observable caps number of emissions on high frequency (#50)
• Error when "closing" a time interval (#52)
• Does rocket.jl support multi-threading and distributed computing? (#53)