Relax semver for most devDependencies

These things are mostly stable, don't change much, not as essential.
Greenkeeper will continue to test upgrade branches anyway, so we will know
quickly if any of these dependencies cause any breakage

package.json

@@ -39,39 +39,39 @@
   },
   "devDependencies": {
     "brfs": "1.4.3",
-    "chai": "~4.1.0",
+    "chai": "^4.1.0",
     "d3": "4.10.0",
-    "ecstatic": "~2.2.0",
+    "ecstatic": "^2.2.0",
     "editor-layer-index": "osmlab/editor-layer-index.git#gh-pages",
-    "gaze": "~1.1.1",
-    "eslint": "~4.3.0",
-    "glob": "~7.1.0",
-    "happen": "~0.3.1",
-    "js-yaml": "~3.9.0",
-    "jsonschema": "~1.1.0",
-    "json-stable-stringify": "~1.0.1",
+    "gaze": "^1.1.1",
+    "eslint": "^4.3.0",
+    "glob": "^7.1.0",
+    "happen": "^0.3.1",
+    "js-yaml": "^3.9.0",
+    "jsonschema": "^1.1.0",
+    "json-stable-stringify": "^1.0.1",
     "@mapbox/maki": "^4.0.0",
     "mapillary-js": "2.6.0",
-    "minimist": "~1.2.0",
-    "mocha": "~3.4.0",
-    "mocha-phantomjs-core": "~2.1.0",
+    "minimist": "^1.2.0",
+    "mocha": "^3.4.0",
+    "mocha-phantomjs-core": "^2.1.0",
     "name-suggestion-index": "0.1.1",
-    "npm-run-all": "~4.0.0",
+    "npm-run-all": "^4.0.0",
     "phantomjs-prebuilt": "~2.1.11",
-    "request": "~2.81.0",
+    "request": "^2.81.0",
     "rollup": "0.45.2",
     "rollup-plugin-commonjs": "8.0.2",
     "rollup-plugin-json": "2.2.0",
     "rollup-plugin-node-resolve": "3.0.0",
-    "shelljs": "~0.7.5",
-    "shx": "~0.2.1",
-    "sinon": "~2.3.0",
-    "sinon-chai": "~2.12.0",
+    "shelljs": "^0.7.5",
+    "shx": "^0.2.1",
+    "sinon": "^2.3.0",
+    "sinon-chai": "^2.12.0",
     "smash": "0.0",
     "svg-sprite": "1.3.7",
-    "uglify-js": "~3.0.0",
-    "xml2js": "~0.4.17",
-    "xmlbuilder": "~9.0.1"
+    "uglify-js": "^3.0.0",
+    "xml2js": "^0.4.17",
+    "xmlbuilder": "^9.0.1"
   },
   "greenkeeper": {
     "label": "chore-greenkeeper"