Update CHANGELOG.md

Merge pull request #39 from cmeissner/issue/38

increase error handling

Merge pull request #29 from cmeissner/release/1.0.0

release 1.0.0

release 0.1.7 (#26)

* add more not found messages
* prepare release

release v0.1.6 (#25)

* handle not found exception for vrf
* prepare release 0.1.6

release v0.1.5 (#24)

* return controller paths not names

Merge pull request #23 from cmeissner/release/v0.1.4

release v0.1.4

release v0.1.3 (#22)

* fix typo
* prepare release

release v0.1.2 (#21)

* detailed exception handling
* prepare release

release v0.1.1 (#20)

As search for a subnet which doesn't exists leads to exit code 200 and
'No subnet found' message we need to adjust the exception handling.
We also add a stupid test for that new exception state.