Fix tracedSVG fragment support in Gatsby 2.0

Initial tracedSVG support did not include fragments for gatsby-image in 2.0, which uses Fixed and Fluid instead of Resolutions and Sizes. Add support for these new fragments.

Author: tylermenezes

packages/gatsby-source-contentful/src/fragments.js

@@ -10,6 +10,16 @@ export const contentfulAssetFixed = graphql`
   }
 `
 
+export const contentfulAssetFixedTracedSVG = graphql`
+  fragment GatsbyContentfulFixed_tracedSVG on ContentfulFixed {
+    tracedSVG
+    width
+    height
+    src
+    srcSet
+  }
+`
+
 export const contentfulAssetFixedNoBase64 = graphql`
   fragment GatsbyContentfulFixed_noBase64 on ContentfulFixed {
     width
@@ -52,6 +62,16 @@ export const contentfulAssetFluid = graphql`
   }
 `
 
+export const contentfulAssetFluidTracedSVG = graphql`
+  fragment GatsbyContentfulFluid_tracedSVG on ContentfulFluid {
+    tracedSVG
+    aspectRatio
+    src
+    srcSet
+    sizes
+  }
+`
+
 export const contentfulAssetFluidNoBase64 = graphql`
   fragment GatsbyContentfulFluid_noBase64 on ContentfulFluid {
     aspectRatio