Update CHANGELOG.md

CHANGELOG.md

-# v1.2.0 (in development)
+# v1.3.0 (in development)
+**User Facing**
+
+**Background**
+
+*Known Bugs*
+* cellranger mkfastq will not accept spaces in path for run param even if quoted, issue raised on 10XGenomics/cellranger github issue [#31](https://github.com/10XGenomics/cellranger/issues/31)
+    * note: 10x doesn't check github issues, emailed instead
+    * note: pipeline checks for spaces and exits prematurely if found
+* If multiple flowcells (tar'd) files are inputted then there will be multiple fastq's by the same name, currently dealing with that name conflict is not tractable
+    * note: if multiple bcl files are detected then cellranger_count design file is not created
+
+# v1.2.0
 **User Facing**
 * Add references to of tools to mutiQC report
 * Add BICF details to multiqc report