Fix linter errors

# Conflicts:
#	lib/contracts/contribution.js
#	lib/contracts/contributor.js
#	lib/contracts/proposal.js
#	lib/kredits.js
#	lib/utils/pagination.js

lib/serializers/contribution.js

@@ -9,7 +9,7 @@ const validator = require('../utils/validator');
  */
 class Contribution {
 
-  constructor(attrs) {
+  constructor (attrs) {
     Object.keys(attrs).forEach(a => this[a] = attrs[a]);
   }
 
@@ -26,24 +26,24 @@ class Contribution {
       kind,
       description,
       url,
-      details
+      details,
     } = this;
 
     let data = {
-      "@context": "https://schema.kosmos.org",
-      "@type": "Contribution",
-      "contributor": {
-        "ipfs": contributorIpfsHash
+      '@context': 'https://schema.kosmos.org',
+      '@type': 'Contribution',
+      'contributor': {
+        'ipfs': contributorIpfsHash,
       },
       date,
       time,
       kind,
       description,
-      "details": details || {}
+      'details': details || {},
     };
 
     if (url) {
-      data["url"] = url;
+      data['url'] = url;
     }
 
     // Write it pretty to ipfs