fix requirements so compatible with graphene and uptick

[thehapax]

Requests must be locked to 2.21 in order to prevent conflict with graphene and uptick.
Uptick must be upgraded to 0.2.4 in order for commands such as uptick commands such as listaccounts and --version to work without throwing errors.

Order of install: 1. requests 2. graphenelib 3. bitshares 4. uptick.

requests==2.21.0
uptick==0.2.4

$ uptick --version
+-------------+---------+
| name | version |
+-------------+---------+
| uptick | 0.2.4 |
| bitshares | 0.3.2 |
| graphenelib | 1.1.18 |
+-------------+---------+

[joelvai]

Merged to devel