bump version 0.3

[relf]

This PR contains:

• the PR fixed GENN theory link in documentation #134 + move neural_net dir under utils dir
• test against py37
• and then a version bump (0.3 as GENN was added)

[AppVeyorBot]

❌ Build SMT 0.3.510 failed (commit d6462b9fa7 by @relf)

[bouhlelma]

It seems this PR responds to the comments of PR 134. Should we close PR 134?

[bouhlelma]

I approved, you can merge it whenever you are ready.

[coveralls]

Coverage increased (+0.5%) to 77.892% when pulling 8cc3cdc on relf:master into ab3bda1 on SMTorg:master.

[AppVeyorBot]

❌ Build SMT 0.3.511 failed (commit 1c98d6bd27 by @relf)

[AppVeyorBot]

❌ Build SMT 0.3.512 failed (commit 9060499fbe by @relf)

[AppVeyorBot]

❌ Build SMT 0.3.513 failed (commit 09ebf950eb by @relf)

[AppVeyorBot]

✅ Build SMT 0.3.514 completed (commit bcdbf3f08c by @relf)

[relf]

I've no problem with my Windows 7, py37 anaconda installation, but appveyor installation still fails due to numpy installation error (though I use same module version numbers)... I deactivate the test for the time being.