v0.4.2

Sunny v0.4.2

Diff since v0.4.1

Closed issues:

• MetropolisSampler should allow adjustable magnitude of updates (#36)
• Occasional segfaults when dipole-dipole interactions are enabled (#65)

Merged pull requests:

• Proper scaling for convergence criterion (#64) (@kbarros)
• Avoid all use of deepcopy (#66) (@kbarros)