v0.7.0

AbInitioSoftwareBase v0.7.0

Diff since v0.6.0

Merged pull requests:

• New version: v0.6.0 (#55) (@singularitti)
• Move MpiexecOptions.path to a global preference (#56) (@singularitti)
• Move MpiexecOptions.path to a global preference (#57) (@singularitti)
• Deprecate type MpiexecOptions & MpiexecConfig & Rewrite mpiexec (#58) (@singularitti)
• Remove docs of MpiexecConfig & Add Preferences.jl to docs (#59) (@singularitti)
• Fix tests in #52 (#60) (@singularitti)