Add router related config to the manager

[Senyoret1]

Did you run make format && make check?
The go code was not changed. npm run lint and npm run build were used.

Changes:

• Now the min and max hops are shown in the right bar of the visor details page. Also, under the data there is a button for being able to change the values.

How to test this PR:
Enter to the visor details page and check the data in the right bar. For changing the values, press the Change configuration button.

Note: the PR will be finished after the API endpoints for getting and setting the data are added.

[Senyoret1]

The last commits include the following changes:

• Now the UI shows the current config and is able to change it.
• The max hops options were removed.
• A help text was added.
• The changes made in Add min hops manipulation endpoint #780 were added to this PR, as are nedded for the changes to work and for the Travis tests.

Now this PR should be ready.