Bump package version for SRP and Postprocessing

ScriptableRenderPipeline/Core/package.json

 {
     "name": "com.unity.render-pipelines.core",
     "description": "Core library for Unity render pipelines.",
-    "version": "0.1.26",
+    "version": "0.1.27",
-        "com.unity.postprocessing": "0.1.7"
+        "com.unity.postprocessing": "0.1.8"
     }
 }

ScriptableRenderPipeline/HDRenderPipeline/package.json

 {
     "name": "com.unity.render-pipelines.high-definition",
     "description": "HD Render Pipeline for Unity.",
-    "version": "0.1.26",
+    "version": "0.1.27",
-        "com.unity.postprocessing": "0.1.7",
-        "com.unity.render-pipelines.core": "0.1.26"
+        "com.unity.postprocessing": "0.1.8",
+        "com.unity.render-pipelines.core": "0.1.27"
     }
 }

ScriptableRenderPipeline/LightweightPipeline/package.json

 {
     "name": "com.unity.render-pipelines.lightweight",
     "description": "Lightweight Render Pipeline for Unity.",
-    "version": "0.1.26",
+    "version": "0.1.27",
-        "com.unity.postprocessing": "0.1.7",
-        "com.unity.render-pipelines.core": "0.1.26"
+        "com.unity.postprocessing": "0.1.8",
+        "com.unity.render-pipelines.core": "0.1.27"
     }
 }

ScriptableRenderPipeline/master-package.json

 {
-    "version": "0.1.26",
+    "version": "0.1.27",
-        "com.unity.postprocessing": "0.1.7"
+        "com.unity.postprocessing": "0.1.8"
     },
     "subPackages": [
         "Core",