upgrade react and material-ui to their latest versions

client/package.json

 {
-    "name": "spot-web-app",
-    "version": "0.1.0",
-    "homepage": "http://spot.lrde.epita.fr/app/",
-    "private": true,
-    "license": "GPL-3.0",
-    "dependencies": {
-        "@material-ui/core": "^1.4.3",
-        "react": "^16.4.2",
-        "react-dom": "^16.4.2",
-        "react-scripts": "1.1.4",
-        "react-svg-inline": "^2.1.1",
-        "typeface-roboto": "0.0.54"
-    },
-    "scripts": {
-        "start": "react-scripts start",
-        "build": "react-scripts build",
-        "test": "react-scripts test --env=jsdom",
-        "eject": "react-scripts eject"
-    }
+  "name": "spot-web-app",
+  "version": "0.1.1",
+  "homepage": "http://spot.lrde.epita.fr/app/",
+  "private": true,
+  "license": "GPL-3.0",
+  "dependencies": {
+    "@material-ui/core": "^3.1.2",
+    "react": "^16.5.2",
+    "react-dom": "^16.5.2",
+    "react-scripts": "2.0.3",
+    "react-svg-inline": "^2.1.1",
+    "typeface-roboto": "0.0.54"
+  },
+  "scripts": {
+    "start": "react-scripts start",
+    "build": "react-scripts build",
+    "test": "react-scripts test --env=jsdom",
+    "eject": "react-scripts eject"
+  },
+  "browserslist": [
+    ">0.2%",
+    "not dead",
+    "not ie <= 11",
+    "not op_mini all"
+  ]
 }