Fixes activation of navlinks

There is some problem with the combination of react-router
and react-bootstrap that causes a single nav link, e.g. users or
subs, to be stuck activated regardless of the actual current url.

I found a fix here
remix-run/react-router#3536
and an explanation here
https://github.com/ReactTraining/react-router/blob/master/packages/react-router/docs/guides/blocked-updates.md

src/components/NavBar/index.js

@@ -39,10 +39,10 @@ const NavBar = (props) => {
         </NavDropdown>
 
           <LinkContainer exact to="/users">
-            <NavItem eventKey={1}>Users</NavItem>
+            <NavItem>Users</NavItem>
           </LinkContainer>
           <LinkContainer exact to="/subs">
-            <NavItem eventKey={2}>Subs</NavItem>
+            <NavItem>Subs</NavItem>
           </LinkContainer>
         </Nav>
         <Nav pullRight className="right-user-links">

src/containers/NavBarContainer/index.js

@@ -15,6 +15,8 @@ const mapDispatchToProps = dispatch => (
 const NavBarContainer = connect(
   null,
   mapDispatchToProps,
+  null,
+  {pure: false},
 )(NavBar)
 
 export default NavBarContainer;