Drop Julia 0.5 and maintenance

Bug fixes

• Fix evalbase ChebParams with scalar argument (#36 and #37)

Enhancements

• Added routines for type stable calls to complete_polynomial (see #33)
• Allow complete_polynomial to be called with any AbstractArray (47a15a1)
• Make sure node(::Basis) always returns (Array, NTuple{N,<:Array})` (ref #38 and 75f93a5)
• Run femtocleaner to clean up pre-0.6 deprecations (#39)
• Better eltype prediction, allowing for use in ForwardDiff.jl (#40 and #41)
• nodes always returns Vector instead of a Range-like thing (9fd30c6)
• Use less memory when evaluating integrals or derivatives of ChebParams (a03a788)

Documentation

• Update readme so struct definitions match actual code (#35 and 7cc768a, 192cc38)