Upgrade to Julia v0.7

0.7updates (#53)

* Updates for 0.7

* Suppress tests on 0.6

v0.6.1: Merge pull request #50 from JuliaStats/sb/travis

enable travis on 0.7

v0.6.0

Merge pull request #41 from JuliaStats/doublebackslash

Double backslashes in math expressions

v0.5.0

Remove 0.4 PkgEval badge, add 0.6

More generic implementations and Julia 0.6 fixes

v0.4.0

Use Int instead of Int64 in function signatures and test integer inpu…