migrating jscs and jshint configs to eslint

for #1508

.eslintrc.jscs

@@ -0,0 +1,20 @@
+{
+  "rules": {
+    "max-len": [
+      2,
+      140
+    ],
+    "indent": [
+      2,
+      4,
+      {
+        "SwitchCase": 1
+      }
+    ],
+    "space-before-function-paren": [
+      2,
+      "always"
+    ],
+    "valid-jsdoc": 2
+  }
+}

.eslintrc.jshint

@@ -0,0 +1,71 @@
+{
+  "env": {
+    "jasmine": true,
+    "node": true,
+    "mocha": true,
+    "browser": true,
+    "builtin": true
+  },
+  "globals": {
+    "dc": false,
+    "d3": false,
+    "crossfilter": false
+  },
+  "rules": {
+    "block-scoped-var": 2,
+    "camelcase": 2,
+    "curly": [
+      2,
+      "all"
+    ],
+    "dot-notation": [
+      2,
+      {
+        "allowKeywords": true
+      }
+    ],
+    "eqeqeq": [
+      2,
+      "allow-null"
+    ],
+    "guard-for-in": 2,
+    "no-caller": 2,
+    "no-cond-assign": [
+      2,
+      "except-parens"
+    ],
+    "no-debugger": 2,
+    "no-empty": 2,
+    "no-eval": 2,
+    "no-extend-native": 2,
+    "no-irregular-whitespace": 2,
+    "no-iterator": 2,
+    "no-loop-func": 2,
+    "no-multi-str": 2,
+    "no-new": 2,
+    "no-proto": 2,
+    "no-script-url": 2,
+    "no-sequences": 2,
+    "no-undef": 2,
+    "no-unused-vars": [
+      "error",
+      {
+        "args": "none"
+      }
+    ],
+    "no-with": 2,
+    "quotes": [
+      2,
+      "single"
+    ],
+    "semi": [
+      0,
+      "never"
+    ],
+    "valid-typeof": 2,
+    "wrap-iife": [
+      2,
+      "inside"
+    ]
+  }
+}