update remix-debug syntax to use const, let and this

remix-debug/package-lock.json

@@ -2561,6 +2561,11 @@
         "randomfill": "^1.0.3"
       }
     },
+    "crypto-js": {
+      "version": "3.1.8",
+      "resolved": "https://registry.npmjs.org/crypto-js/-/crypto-js-3.1.8.tgz",
+      "integrity": "sha1-cV8HC/YBTyrpkqmLOSkli3E/CNU="
+    },
     "d": {
       "version": "1.0.1",
       "resolved": "https://registry.npmjs.org/d/-/d-1.0.1.tgz",
@@ -3497,6 +3502,38 @@
         }
       }
     },
+    "ethers": {
+      "version": "4.0.41",
+      "resolved": "https://registry.npmjs.org/ethers/-/ethers-4.0.41.tgz",
+      "integrity": "sha512-QpW2CPZajquwiA7rVDozMksOuvdUBKIruamAakt0++EKBB/VWtLB9zSRZDInLDpp9fZYgOT/0trPD38r6CzLIg==",
+      "requires": {
+        "aes-js": "3.0.0",
+        "bn.js": "^4.4.0",
+        "elliptic": "6.5.2",
+        "hash.js": "1.1.3",
+        "js-sha3": "0.5.7",
+        "scrypt-js": "2.0.4",
+        "setimmediate": "1.0.4",
+        "uuid": "2.0.1",
+        "xmlhttprequest": "1.8.0"
+      },
+      "dependencies": {
+        "hash.js": {
+          "version": "1.1.3",
+          "resolved": "https://registry.npmjs.org/hash.js/-/hash.js-1.1.3.tgz",
+          "integrity": "sha512-/UETyP0W22QILqS+6HowevwhEFJ3MBJnwTf75Qob9Wz9t0DPuisL8kW8YZMK62dHAKE1c1p+gY1TtOLY+USEHA==",
+          "requires": {
+            "inherits": "^2.0.3",
+            "minimalistic-assert": "^1.0.0"
+          }
+        },
+        "js-sha3": {
+          "version": "0.5.7",
+          "resolved": "https://registry.npmjs.org/js-sha3/-/js-sha3-0.5.7.tgz",
+          "integrity": "sha1-DU/9gALVMzqrr0oj7tL2N0yfKOc="
+        }
+      }
+    },
     "ethjs-unit": {
       "version": "0.1.6",
       "resolved": "https://registry.npmjs.org/ethjs-unit/-/ethjs-unit-0.1.6.tgz",
@@ -3537,6 +3574,11 @@
       "resolved": "https://registry.npmjs.org/eventemitter3/-/eventemitter3-3.1.2.tgz",
       "integrity": "sha512-tvtQIeLVHjDkJYnzf2dgVMxfuSGJeM/7UCG17TT4EumTfNtF+0nebF/4zWOIkCreAbtNqhGEboB6BWrwqNaw4Q=="
     },
+    "events": {
+      "version": "3.0.0",
+      "resolved": "https://registry.npmjs.org/events/-/events-3.0.0.tgz",
+      "integrity": "sha512-Dc381HFWJzEOhQ+d8pkNon++bk9h6cdAoAj4iE6Q4y6xgTzySWXlKn05/TVNpjnfRqi/X0EpJEJohPjNI3zpVA=="
+    },
     "evp_bytestokey": {
       "version": "1.0.3",
       "resolved": "https://registry.npmjs.org/evp_bytestokey/-/evp_bytestokey-1.0.3.tgz",
@@ -5865,6 +5907,11 @@
       "resolved": "https://registry.npmjs.org/safer-buffer/-/safer-buffer-2.1.2.tgz",
       "integrity": "sha512-YZo3K82SD7Riyi0E1EQPojLz7kpepnSQI9IyPbHHg1XXXevb5dJI7tpyN2ADxGcQbHG7vcyRHk0cbwqcQriUtg=="
     },
+    "scrypt-js": {
+      "version": "2.0.4",
+      "resolved": "https://registry.npmjs.org/scrypt-js/-/scrypt-js-2.0.4.tgz",
+      "integrity": "sha512-4KsaGcPnuhtCZQCxFxN3GVYIhKFPTdLd8PLC552XwbMndtD0cjRFAhDuuydXQ0h08ZfPgzqe6EKHozpuH74iDw=="
+    },
     "scryptsy": {
       "version": "2.1.0",
       "resolved": "https://registry.npmjs.org/scryptsy/-/scryptsy-2.1.0.tgz",
@@ -7287,6 +7334,11 @@
         "xhr-request": "^1.0.1"
       }
     },
+    "xhr2": {
+      "version": "0.2.0",
+      "resolved": "https://registry.npmjs.org/xhr2/-/xhr2-0.2.0.tgz",
+      "integrity": "sha512-BDtiD0i2iKPK/S8OAZfpk6tyzEDnKKSjxWHcMBVmh+LuqJ8A32qXTyOx+TVOg2dKvq6zGBq2sgKPkEeRs1qTRA=="
+    },
     "xhr2-cookies": {
       "version": "1.1.0",
       "resolved": "https://registry.npmjs.org/xhr2-cookies/-/xhr2-cookies-1.1.0.tgz",

remix-debug/src/debugger/solidityState.js

@@ -68,7 +68,7 @@ class DebuggerSolidityState {
   }
 
   extractStateVariables (stateVars, address) {
-    var storageViewer = new StorageViewer({ stepIndex: this.stepManager.currentStepIndex, tx: this.tx, address: address }, this.storageResolver, this.traceManager)
+    let storageViewer = new StorageViewer({ stepIndex: this.stepManager.currentStepIndex, tx: this.tx, address: address }, this.storageResolver, this.traceManager)
     stateDecoder.decodeState(stateVars, storageViewer).then((result) => {
       this.event.trigger('solidityStateMessage', [''])
       if (result.error) {