Force schedule columns to float

[rajeee]

Addresses #352

Sometimes a building's particular schedule column can have integer only values which results in pandas assigning integer datatype to that column. But this causes problem when generating the metadata during postprocessing since other schedule file can have float datatypes. This PR fixes the issue by always interpreting the schedule values as float during read.

[github-actions]

File	Coverage
All files	84%	✅
base.py	89%	✅
eagle.py	74%	✅
exc.py	57%	✅
local.py	50%	✅
postprocessing.py	85%	✅
utils.py	96%	✅
sampler/base.py	79%	✅
sampler/downselect.py	33%	✅
sampler/precomputed.py	93%	✅
sampler/residential_quota.py	61%	✅
test/test_docker.py	33%	✅
test/test_validation.py	97%	✅
workflow_generator/base.py	90%	✅
workflow_generator/commercial.py	53%	✅
workflow_generator/residential.py	96%	✅
workflow_generator/residential_hpxml.py	69%	✅

Minimum allowed coverage is 33%

Generated by 🐒 cobertura-action against cdfa113

[nmerket]

Can you put in a changelog entry for this?