Only attempt to compute genotype value if self.genotype is valid

Since the genotype field is nullable there is no guarantee that it will be present in call cases so we need to check for its existence before attempting to access properties of it.

From internal change on 11/21
Move vcf_colname to default attributes rather than part of the lookup

From internal change on 11/22
Make sample name optional in /workspace/<project>/<batch>/<sample>/ urls

From internal merge on 12/2
Use absolute positioning on analysis button instead of floating right

From internal merge on 12/2
Update Avocado to 2.0.24 Serrano to 2.0.16 and Cilantro to 2.0.11

From internal changes on 12/4
Add commands to delete projects and samples

From internal merge on 12/4
Update HGMD SNP loader to match on HGVS

From internal merge on 12/6
Remove clumsy comment within a multi-line SQL statement

Fix load_hpo method to take the using argument.

From internal change on 12/6
Print total count to see progress

From internal change on 12/6
Add checks for 'EFF' key when processing variant data

This key is not always there and was causing key errors in the tests. Now, the code properly ignores the effects for variants without this key by checking if the 'EFF' key exists before trying to access and process it.

From internal change on 12/6
Re-enable check if any samples are created before publishing to channel

Without this enabled, files will be queued up to be processed every time they are scanned.

From internal change on 12/9
Protect against null return values from load_sample call

From internal merge on 12/9
Add python script to update allele freqs when default queue becomes empty

From internal merge on 12/10
Add ability to filter by zygosity using genotype field

From internal merge on 12/10
Fix mistyped check of the load flag in manifests

From internal change on 12/10
Wrap load_samples in try/except in sample queue

This prevent stopping the queue process for faulty samples

From internal change on 12/10
Stop testing on Django 1.6

Harvest doesn't so neither will we for now
Update travis file to install necessary packages when using Python 2.6
Limit delete test to batch1 and fix sample name in lookup
Add missing - in travis install section