Graph Prop: isInteractive (#56)

* feat(props): add isInteractive

* refactor(selection): dont allow if not interactive

* feat(renderer): add class if is interactive

* chore(inactive): add tests

* refactor(inactive): no connection line, no edge selection

closes #49

src/style.css

@@ -67,7 +67,9 @@
 }
 
 @keyframes dashdraw {
-  from {stroke-dashoffset: 10}
+  from {
+    stroke-dashoffset: 10;
+  }
 }
 
 .react-flow__nodes {
@@ -79,21 +81,30 @@
   transform-origin: 0 0;
 }
 
+.is-interactive {
+  .react-flow__node {
+    cursor: grab;
+
+    &:hover > * {
+      box-shadow: 0 1px 5px 2px rgba(0, 0, 0, 0.08);
+    }
+  }
+
+  .react-flow__handle {
+    cursor: crosshair;
+  }
+}
+
 .react-flow__node {
   position: absolute;
   color: #222;
   font-family: sans-serif;
   font-size: 12px;
   text-align: center;
-  cursor: grab;
   user-select: none;
   pointer-events: all;
   transform-origin: 0 0;
 
-  &:hover > * {
-    box-shadow: 0 1px 5px 2px rgba(0, 0, 0, 0.08);
-  }
-
   &.selected > * {
     box-shadow: 0 0 0 2px #555;
   }
@@ -104,7 +115,6 @@
   width: 10px;
   height: 8px;
   background: rgba(255, 255, 255, 0.4);
-  cursor: crosshair;
 
   &.bottom {
     top: auto;
@@ -123,7 +133,6 @@
     top: 50%;
     left: 0;
     transform: translate(0, -50%);
-
   }
 
   &.right {