[FIX] used tx_hash
[#364] raise error when previous hash is None + fix indentation
Merge pull request #366 from JahPowerBit/develop2

[#364] raise error when previous hash is None + fix indentation
Merge pull request #365 from Ignat99/sochainpy

[FIX] used tx_hash
[PIP] new versions in pip-requirements.txt
Merge pull request #367 from Ignat99/piprequirements

[PIP] new versions in pip-requirements.txt
typo
updated and cleaned up README
further work on README
log lock acquisition
replace lockfile with singleton
moved singleton check to appropriate place
[#338] refresh next tx_index when there is a reorg
Merge pull request #377 from JahPowerBit/develop3

[#338] refresh next tx_index when there is a reorg
fixes #375
Add ToC

Table of Contents
Merge pull request #380 from rippler/patch-3

Add ToC
catch TypeError in API
TODO: generalise for all API methods
Merge pull request #381 from JahPowerBit/develop3

catch TypeError in API