v0.9.1

MortalityTables v0.9.1

Diff since v0.8.5

Closed issues:

• Underyling structure of Mortality Tables (#8)
• Add Joint Life Mortality (#43)
• Create an iterable interface (#54)

Merged pull requests:

• drop unecessary MortalityVector layer (#53) (@alecloudenback)
• Major Refector of API and internals (#55) (@alecloudenback)
• use @views to reduce allocation and increase performance (#57) (@alecloudenback)