Allowing specific actions to be restricted to specific fieldsets

This allows `Form#input()` and `Form#serialize()` to be limited to a
specific `<fieldset>`. (also updates `dominicbarnes/form-serialize`
to `0.1.1` which drops the `loose` parameter)
pinning dependencies to semver ranges
version bump + changelog update
Merge branch 'release/0.1.0'
Merge tag '0.1.0' into dev

v0.1.0 release
 * updates [form-serialize](https://github.com/dominicbarnes/form-serialize) and drops `loose` parameter
 * added ability for `Form#input()` and `Form#serialize()` to filter by `<fieldset name="...">`
 * pinning dependencies to specific semver ranges (instead of `*`)